The warlock community got excited ever since the announcement came out that affliction warlocks would get a similar treatment to the change shadow priests got that allowed mind flay to crit. I was a bit skeptical about allowing warlock DoT's to crit because warlocks do so much damage already and they're well off with their non-critting DoT's. But the announceent was made that said a new affliction talent would be implemented and the keywords would be "Dot's" and "Crit". There was a lot of speculation exactly how this would be implemented and the affliction warlock inside of me (currently level 56) was hoping that at least the basic DoT's would get even a small chance fixed to crit. To some extent, that's what eventually happened.
The new talent is called Pandemic and it's on the same tier as Unstable Affliction and also has UA as a prerequisite. basically what it does is that every time your Corruption and Unstable Affliction spells damage a target, it has a chance equal to your crit chance to deal 33%/66%/100% more damage. At max rank, every time this procs means it's like actually critting. It's one of those talents that's nice to have and definitely has that coolness factor too see it go off especially since Corruption and UA are two of the hardest hitting DoT's around. But it also is a poor reason to start stacking as much crit as say mages, in my opinion. Spell hit is still king for PvE affliction warlocks and Pandemic is just like an icing on the cake. I shudder to see this talent in action for PvP when UA gets dispelled. Whammo!