Before we get rolling I wanted to link to this site. He doesn't always have complimentary things to say but I find the candor refreshing, and it's nice to see this post. Yes, a paladin/warrior team does well in the arenas. No, it's not the end of the freaking world. Quite honestly, anything that gets paladins and warriors to cooperate is a good thing in my opinion. There are some good posts back in the archive there on PvP builds, various spec issues, patch notes and so on. And this post about Black Morass and Shattered Halls mirrors my own views exactly. If you're interested in warriors, especially arms warriors, you should go give it a look see.
Now, to discuss the warrior. Specifically, the future of the warrior in 2.3, as I managed to port my horde warrior over to test this week and played around with specs as much as my limited gold allowed (getting an initial free respec helped). Things to tell you up front: a 41/5/15 arms/fury/prot build can tank heroics with average tanking gear now. I'm talking Latro's Shifting Sword as a tanking weapon average. I did heroic Mana Tombs and heroic Sethekk on test with minimal issue (the warlock pulled aggro a couple of times, nothing earth shattering, I got it back) and so far as I could tell without being able to use a threat meter because I forgot to install one, Mortal Strike is getting the threat bonus they promised from Tactical Mastery.
So it seems to me that, if things continue as I've experienced them, we may be looking at the return of the Arms warrior as the default, cookie cutter spec. And to be honest, I don't know if I like that idea.