im pretty sure that peggleftw was referring to the difference between both warlock spells.
answer: There isn't much of a difference, but someone speculated shadowfury to be better for PVE.
I always wondered why we had a death coil at all, The DK's had it patented first technically and theirs actually works how the WarcraftIII one worked (more or less)
And the warlock death coil was the warcraft 2 one with an added horror effect. Additionally, the warcraft 2 death knights were dead warlock spirits processing the corpses of human soldiers. Warlocks having DC was never out of place really, until they had to share a skill name with DKs.
Taking away baseline abilities like howl of terror and DC seems really lame thou, so does taking away the damage from shadowfury and our new version of death coil.
I don't mind the name change, the healing increase is pretty crazy if it stays that way. I just hope all warlocks wont be casting all dots. Destro casting corruption is silly, I don't mind banes but rather wouldn't use them. In my head we should only cast spells that are in our specs spellbook page, only in PvE of course to just dps.
There isn't going to be diversity between players thou, just diversity between encounters. Since you can swap them on the fly, you'll always just be swapping to what makes more sense for what you're doing next, which will be the same as any other (competent) person as the same class/spec in the same situation. Eg: what lock is going to spec into howl of terror/shadowfury for a boss fight with unavoidable raid damage, and no CCable adds?
I'll be using Mortal Coil in PVE, and PVP. 25% heal is just too big to give up IMO. This is why I love these talent trees -OPTIONS!
I think that most of the time the healing from Soul Leech should make it unnecessary, especially when you can mitigate so much damage through Soul Link/Nether Ward in addition (boy do I hope they revert the split healing from soul link somewhere down the line). Shadowfury is just way too useful to pass up.
The amount of utility that shadowfury has is kind of ridiculous. Its a pretty unique spell, as AE stuns are uncommon as it is, but a targeted/long ranged AE stun at that.
Obviously the PvP comp and setting you're playing in while greatly determine which you take (Sharing stun DR or fear DR or the necessity of that healing CD) , being able to pick up shadowfury in any of the 3 PvE specs w/ no punishment is very very nice.
I think that the passive selfhealin will go away, thats why we see so many active healing talents