Ninja, way better than every other class.

[KaedrianLiang]

I have yet to see a MMO release a new race/class and not give some feature out of balance with existing races/classes.

oh my gawd. For those that played WotLK. Dealing with Death Knights the first 3 months, especially unholy specced that came back to life as a ghoul, immune for like 5 seconds while coming back to life to finish you off after spending sweat and blood trying to kill it. The nightmares.