a one-time feral druid whos a friend of mine spoke about his DPS ability while still running kara. hes resto now, and has been for while, so his memory is a big foggy, but i think fully buffed while in kara from a group that regularly cleared kara, he was getting ticks over 600 or so.
this was with mangle, trinkets, blood frenzy on mob, and any other applicable stuff (str of earth, grace of air etc.).
pre-patch, id fight feral druids as my warrior who would get ticks of ~450 on me with mangle up while i was in battle stance.