It's a nice idea (which has been mentioned countless times) but the idea is a lot easier to imagine than actually implementing it.

People WILL boast about their DPS, (can totally see E-peen arguments here) and demand other players DPS information for things like farms or statics. I support the idea but it needs to be thoroughly thought out and implemented in a certain way or it will cause more problems than it will solve.

Also, DPS means nothing if you can't execute mechanics correctly.