I personally like HDR, but would only use it for single player or non-competetive online gaming - otherwise the FPS hit is just too high.
Problem with HDR is in my opinion is that it's came too early. Sure, it looks great when you leave a cave and enter a sunny day - but in real life, you witness this sort of effect a lot more. Hell, I had a BBQ today, looked at the greasy sausages, and noticed a HDR-type effect on them. But that'd look out of place in games today, as you'd never have sausages that detailed. Ok, a very odd example, but you get my meaning - HDR should apply to many more objects rather than the sky, armour and buildings.
-RaZ