Here is my sad story of how I got my Nexus One on January 7 and it was broken by January 8. I was just hanging out with my Nexus One in my pocket. Pulled it out and the screen looked funny. By the next morning, it was all black. It wasn't until I looked closer in bright light that I noticed several cracks in the internal screen, coming from the edges.
I think this is going to be a big problem for this phone. I've dropped my G1 about 20 times over the past 15 months and it's fine. I've even dunked it in a glass of water, dried it out, and it's fine. I did nothing out of the ordinary to my Nexus One and the screen (inside! with no external damage whatsoever) is cracked and now does not work. This is lousy manufacturing.
I put a call into HTC and they are supposed to be sending me a fedex label to send them the phone, but I didn't tell them the screen is cracked, I just said the screen doesn't work. So I am expecting them to tell me I'll have to pay to replace the screen. The warranty number for HTC is 888-617-1113. By the way it's been 24 hours and I still haven't received the emailed fedex label, so I am growing concerned...
Also, there is a company in Dallas called dr cell phone (google it) which can repair screens the same day they receive your phone, you can just ship it to them. It costs somewhere between $75 and $175 and they said they will repair the Nexus One (they do many other HTC phones). However they told me they are waiting on parts from HTC so it could be 1-2 weeks before they get parts.
I'll try to update when I get this resolved...right now, I am back using my trusty G1, with a great looking brick sitting in a box on my desk.