I've done a bit of reading on it and I like the DLP's over the lcd's or plasma. Although, I'm not opposed to a rear projection setup. If your bent on getting a flat screen (wall mount), I don't know if DLP technology applies.
I was looking at a front projection DLP unit. A good one runs about 4G's though. They don't have a real long light life. But, pretty much all hi-def rear projection tv's use the same type of light system as a front projection, so light life would probably be similar (2000 hours in general).
We currently have an old school non-hi-def hitachi 60" rear projection. We've had it for almost 7 years. I took it apart and cleaned the light guns, mirror and back of the screen about 5 months ago. It became as clear and as bright as it was the day we bought it... here I was doing it as a last ditch effort to avoid buying a new TV and I got like new results.
It's still one of the clearest and brightest non high-def units I've seen.