I agree, self defense laws have gone too far to the other side. One has to not only protect himself, but in the heat of battle, make very precise judgements on lethal force. This is the law however, and we should know it, follow it carefully, to be able to defend ourselves against both an attacker and the inevitable criminal and civil legal action.
There are a lot of misconceptions out there, particularly about "consensual fighting" and use of lethal force in self-defense.
FWIW, IANAL, your mileage, state and D.A. may vary:
Legal Definition of Self Defense
Mutual combat upon a sudden quarrel? Gotta be something a lawyer dreamed up. Silly. Part of it also negates the first article listed as how can you know wether or not your attacker means to end you in a bar fight? Shouldn't that just be pre-supposed?
Then again, I'm not the type to swing first either. I may be biased.