Yeah my warrior is 83, fury spec, and about 1/3 of my gear is prot, but with the huge amounts of strength even from quests reward/dungeon blue gear, I can comfortably do 8000-10,000 dps.
I haven't yet tried tanking in Cata dungeons, but I assume it wouldn't be that much different to level 80 WotLK heroics.
All in all, really enjoying my warrior - has 89,000 hp when buffed
What are rogues like to level (quests/dungeons etc)? I have a level 12 rogue I think, with full BOA's and enchants. Good to play so far and doesn't seem like too much downtime.
Also have a 70 warlock in BOA's....also good to level and to play @ end game??