Same problem with our '02 GMC 2500HD. Driver's side DRL went out (the usual one, although our truck supposedly had the upgraded bulbs). Pulled the socket out of the housing and the whole thing is black. Broke part of it trying to pull the bulb out. I was _really_ afraid I was going to break the bulb pulling it, I was using so much force. It is supposed to just pull out. Got it changed. I'd like to replace the socket.
The problem is probably the problem with most of the light harness, the wires are too small, causing too much resistance and making too much heat. It doesn't help that the things are on all the time. If I find another socket, I may try bigger wires to see if that doesn't help the situation.
Yeah, DRLs are pretty stupid, now that everyone runs them (except the cops). But I'd still like to run with them, given the 'bright flashy thing distracts me' mentality of most of today's drivers. Maybe one little light will prevent me getting balled up by Soccer Mom in her lifted diesel Excursion while she is yaking on the phone putting makeup on, running through that intersection.