I'm currently working on leveling my priest right now (78 at the moment), so I haven't played with this ability first-hand, but Rogues get a fun tool to look forward to at level 80: Fan of Knives. This significantly helps address one of Rogues' long-time weakness: AoE damage. Sure, we're great on a single target, but it's very difficult to build up CP and use them effectively on poly-mob pulls, and Blade Flurry only goes so far. Hence FoK, which is well-timed given how much AoE there seems to be in Wrath. It also gives you something to do when you need to be at range, which happens from time to time.
But FoK has a ten-second cooldown, which certainly limits how much you can use it - for now. Ghostcrawler recently popped his crabby head into the Rogue forums to announce that "We think we are going to remove the cooldown of Fan of Knives altogether." Yay! I would assume this is going to be coming in the next patch, which they keep saying is coming before 3.1, the Ulduar patch. Patch 3.0.4 Rogues, now with ten times the knife-fanning action!
And as if that wasn't enough nice news from GC, he also said "in case it gets asked, Feral druids we haven't forgotten about your AE either." Hmmm, I say. I have also faced this issue on my druid in cat form - I don't really want to go Bear to Swipe, because then I run a high risk of pulling off the tank, but cat form has literally nothing that hits more than one target. I wonder what they're going to give us. Any predictions?