When I did WOTLK, my tank was only 81; so I couldn't just grab the whole instance and AE it down. I pretty much had my DKs follow my pally around and killed stuff more-or-less legitimately. They died sometimes due to annoying mechanics, but it wasn't a constant thing. [i.e. I usually had to solo the boss fights with them sitting pretty far away]. I found the XP/Hour to not be amazing, but far higher than straight questing. I figured I could do the same thing in Cata if my tank were bigger, but maybe not from what your saying.

Still, its the other major option, since BGs are definitely crappy...