#51 - Jan. 10, 2009, 1:40 a.m.
I am almost positive the talent is looking at your spells. So if you cast Wrath, it does a check to see if you also have FF up on the target.
The intent of the talent is to encourage you to cast Faerie Fire, compensating you a little for the fact that you are debuffing the target. It isn't intended to just be "here have some crit." The intent is that if you cast FF, even if the debuff is already on the mob, you are rewarded for it.
I suspect it isn't smart enough to detect Feral Faerie Fire now that it's a base spell, so we should probably fix the case of a Balance druid who casts FFF and then goes back to Wrath or whatever.
I am just guessing based on the way spells usually work. I did not try this myself so I could be wrong.
I will also admit that there are some inconsistencies currently in the game between whether you are supposed to apply a debuff again on a mob that already has it (because sometimes you get a "More Powerful Spell" error). This is something we're trying to clean up though.