Mind Spike is the new spammable Shadowfrost nuke spell for shadow priests. The way it is going to work is that it places a debuff onto the target which improves subsequent Mind Spike damage, ultimately resulting in DPS about on par with a Shadow Word: Pain/Mind Flay combo. Also, because this is not a Shadow spell, but rather Shadowfrost, it will not get locked when getting locked out of the Shadow school, giving priests an option other than Holy Fire and Smite.
Pros: Mind Spike will give shadow priests something to cast when locked out of the Shadow school of spells (that won't take you out of Shadowform), and something to throw out during fights which require a higher amount of movement (where it may be detrimental to cast a Mind Blast). It will also give Holy/Disc Priests (assuming it is a baseline spell) something to cast that might actually do some damage if necessary.
Cons: If the intent is that this will be used on trash, I think that Blizzard still doesn't have things quite right, unless they change significantly how trash is handled in the expansion (where you actually need to perform crowd control again). I really only think that this will end up being useful in trash packs of 2-3 mobs; any more, and most priests will use Mind Sear; any less, and your normal spell priority will likely do more damage.
Other Thoughts: It perplexes me as to why the developers decided on a Shadow/Frost combination spell, because priests otherwise don't use frost spells at all. A Shadow/Holy spell would have made more sense, but perhaps it was because of the whole dropping out of Shadowform when casting holy spells issue, or because the game doesn't allow for Holy Resistance that the developers decided against a Shadow/Holy combination. In the end, I still feel that this is a much needed spell that will likely be beneficial for all shadow priests.
Grade: B+ (for finally making us able to do something when getting spell locked).
HoTs and DoTs and Death...Oh, My!
Another change that we can expect (assuming they don't change their mind once again) is that ALL HoTs and DoTs will be benefiting from Haste and Critical Strike. While Vampiric Touch and Devouring Plague already do benefit from both stats, Shadow Word: Pain does not right now (it did at one time on the Public Test Realm).
While this may seem like a pretty basic change on the cover, if you look more into what they stated with the change, it becomes more interesting. Basically, hasted HoTs/DoTs will last for the same amount of time as a non-hasted HoT/DoT, but will tick faster (meaning you will "gain extra ticks to fill in the duration"). Along with that, re-casting a spell will no longer reset the ticks, but will simply refresh the HoT/DoT. What this really means is that if you have to re-cast a HoT/DoT, it shouldn't significantly impact your DPS if you are early, but if you wait too long after, it may be detrimental to your DPS.
In the same section as the HoT/DoT changes, you will find that there are planned changes to Shadow Word: Death. While they didn't go into much detail, they did mention that they want to bring it back as an "execute", or something that you are doing when the target is at or below 25% health. Here's to hoping that they either reduce or eliminate the backlash from it (I know I am not the only one to accidentally kill my self by using it on Hodir).
Pros: Less restrictive HoT/DoT management may make shadow priests a bit easier to play and make DPS a bit more consistent for people at similar gear levels.
Cons: Bringing back SWD makes spell casting priority a bit more difficult than it has been in Wrath, but from previous experience, it still shouldn't be that bad, as long as the backlash is less likely to kill people on gimmick fights.
Other Thoughts: The HoT/DoT changes should make spell casting priority choosing a bit easier, perhaps allowing for a "rotation" instead, which should make casting a little easier. Also, I did miss haste affecting SWP in Wrath, I had the opportunity to play with it a bit on the PTR, and it seemed like a nice addition that I am really looking forward to. However, the changes to SWD have me most intrigued right now, because I would really like to see something that could potentially increase our damage once we get to to the "execute" range of a fight.
Grade: B (for fixing things that we had a taste of in the past).
Talent Changes New and Old
Blizzard has come out and said that they want to improve Shadow for short fights (because they finally realize that it is a problem), as well, because they are trying to do away with passive damage-boosting abilities as a whole, it looks like the Shadow tree is going to get a major overhaul. Additionally, the developers are getting rid of pretty much all talents that affect spell hit, so not only are they changing the game play of Spriests, they are also significantly changing how we will select gear (likely making us compete even more for gear that mages/warlocks want).
In addition to the loss of the hit rating benefit of Misery, we will also be losing one of our two largest buffs in Prayer of Spirit, pretty much leaving us with two buffs (Fortitude and Shadow Protection), both of which can be brought to a raid in different forms (Runescroll of Fortitude andShadow Protection Aura), which means that one of the main reasons from Burning Crusade to bring a priest over other classes (their buffs) has basically been eliminated over the course of two expansions (in Wrath, Replenishment became available through other classes).
Pros: Selecting gear for your shadow priest may become more of a linear process, meaning that upgrades to your gear will likely be more defined.
Cons: Priests look to be losing a lot of the buffs that they bring to a raid, meaning they will be less sought after overall. Why bring a priest when you can bring a shaman or druid?
Other Thoughts: It seems to me that the changes to hit rating buffs is related to making updating the game easier for developers. Just think, if they make it so that their is only one number to adjust with regards to damage increases, the number can simply be stored in the database, meaning they can update the value on the fly as a hotfix, whereas if the necessary changes must take place in a calculation, they would likely have to update the entire game, meaning it could be weeks before anything is actually changed.
Grade: C- (for removing reasons to actually bring a priest into the group).
Masters of our Universe
One of the biggest changes that we are likely to see in Cataclysm is the introduction of Mastery bonuses. These are passive bonuses that we will receive simply for putting more points into our main tree (from what I understand, you will only receive bonuses for your "main" tree). Shadow's main bonuses are simply changing the talents that provide passive damage-boosting effects into passive damage-boosting effects simply for having points in the tree. However, the third bonus is something that is entirely new to the game: Shadow Orbs.
From how I understand the Shadow Orbs, you will build up orbs through your normal "rotation" while DPSing, and will be able to consume the orbs when we feel it is time to do so (perhaps you can consume them during Bloodlust/Heroism in order to pump out some impressive damage.
Pros: The replacement of our passive talents with passive bonuses from simply taking talents I think will be a rather nice change, allowing more variation in talent specs. Along with that, the Shadow Orbs seem intriguing to the extent that they may add a bit more complexity to the shadow priest game (because you know we need more complexity to our gameplay).
Cons: With Shadow Orbs being a relatively new mechanic for spriests, I can forsee many complications with the implementation at the start. Also, new mechanics usually feel clunky at the beginning.
Other Thoughts: The Shadow Orbs may make lower level shadow priests feel more "shadowy", and I don't expect them to be too hard to get a handle on, because if you play a shadow priest, you are likely a relatively adaptive player (as is the nature of the class). However, I just hope that the Shadow Orbs don't look like purple Thorns that circle around us.
Grade: B+ (for making rather simple changes, and adding something new and interesting).
One change that I am looking forward to is a new buff called Inner Will, which provides a run speed increase, and mana cost reduction. This buff will share a buff slot with Inner Fire, but they are removing the stacking nature of the buff (so that it doesn't disappear when you get damaged). From what I understand, it looks like Inner Will will likely be more of a healing oriented buff, but it will probably have applications for shadow priests as well. Also because of the nature of the spell, it will likely have PvP applications (run away from those darn melee faster, and using less mana when attacking).
It does look like Inner Will is going to be able to stack with other run speed increasing buffs (Tuskarr's Vitality for instance), and I am sure that there will be fights where we will be able to take advantage of the mana reduction (General Vezax-esque fights perhaps?).
Pros: A new buff that will allow more flexibility without having to micromanage should be interesting. It also seems like it will be useful when/if you are having mana issues for certain fights.
Cons: The buff really seems like it will be very fight specific, and will likely be almost useless when overgearing a fight.
Grade: A- (for providing something actually useful)
Overall Grade: B
Final Thoughts: Some of the changes look like they will offer a bit of a change-up for existing shadow priests (which I suspect many will not like), and some of the changes look like they are doing more harm than good in the end (is it really necessary to remove all of our buffs, and basically all reason to include us in a raid?) . Overall however, I don't think the changes are really that bad, or that good; rather that it will be business as usual for shadow priests (which may not be a good thing).
See you in the Shadows,