With the increased amount of AoE needed in current instances, Blizz has thrown Rogues and Kitties a bone by increasing their AoE abilities.
Rogues will no longer have a CD for Fan of Knives (currently 10 seconds), and they're re-doing the way damage is calculated to make it a little more effective.
Kitties will be given a new swipe ability as a base ability.
Here's the link to the Blue post in the official WoW forums.
(coming in a minor content patch if your too lazy to click on the link, should be on the PTR soonish)
I'm not sure how useful these abilities will be in leveling. (If your not 80 yet)
Druid Balance specs have been given amazing AoE in WOTLK, i'm a slow quester myself, and i've heard the first Druid to hit 80 actually did a ton of AoE farming, from what i read some people that AoE level say they can clear 250-350k per hour of XP unrested.
I decided to give it a go myself in Dragonblight for an hour and only managed to do about 400k WITH RESTED. Not too horrible (and definitely faster than my questing abilities) but still not as high as i would of liked.
So for those that don't know the numbers, for me (and a few people i've spoken to) it takes us about 7 hours of played time to do a level, with my the AoE grind (provided i have rested XP) i should be able to clear a level in about 3-4 hours.
At the moment it's about 1.5 million XP per level, mind you i'm only level 74 still (i know i know hurry up and get to 80 so i can post some guides)
I doubt Kitty swipe will be as effective as Moonkin (and possibly) Resto grinding, but Fan of Knives definitely looks like it may have some prospects, i'll have to work on my Rogue some more to know for sure.