My old guild leader from 6-7 years ago boxed a ranger and shammy, and he swore by it. I've never played either, so can't comment myself.
Currently boxing DRU/ENC/MAG, not through any specific planning, it just sorta happened over the years :) Probably nowhere near optimal, but it works for me.
Plus, at the speed I level, changing classes now would be a killer!
Tat