This. Oh so much this.
I've been leveling my 2nd Druid recently (halfway through 84, Primarily Bear with Kitty off-spec) & dps pulling mobs instead of me annoys the HELL out of me. same with my Prot Pally, & I know I'm not alone.
If the tank asks for you to tricks & pull then by all means. but remember OP. You are NOT the tank.