I've been splitting time these days working on various dailies mostly on my paladin, and then working on leveling my warrior. I've been really pleasantly surprised by how much I've been enjoying leveling the warrior. Now I will admit, it may have something to do with the fact that he's totally tricked out in full BoA's which means he's wreaking total havoc with everything that gets in his way, but it's still tremendous fun.
I'm leveling as Arms - mostly because I already had a good two-hander BoA sword. It seems to be a pretty vicious spec though - the combination of Victory Rush and Mortal Strike seems to put most things pretty quickly on the ground.
I've been able to get him to level 40 pretty quickly. I've been enjoying all of the new quests. While I started him as a goblin, I've actually been leveling over in Eastern Kingdoms just because I really wanted to see all the new quests in Silverpine, Plaguelands, etc. It has definitely not disappointed!
I was intending do try tanking in some dungeons, but I've been enjoying the new quests so much, I haven't really felt the need to bother. That might change once I hit Outland in a few more levels and get back to the same old same old.