Root and Warranty?
I bought my Desire a while back in HK, where I live. I was repartitioning the phone's SD card for an ext-3 partition for this ROM that required it. It messed up somewhere, and broke my phone and the current ROM. I reset to factory, and it wouldn't detect SD card and computer. (so can't RUU).
So I just packed it up and sent it to the HTC Service Center in HK. 3 days later, they called me and told me to pick it up. They said that they put in a new ROM chip (not the custom firmware ROM). It was rooted but they still fixed it for free.
Don't know about you US folks, but it WAS rooted but they still DID fix it for free. Just thought I'd let you know.
P.S.: Unrevoked doesn't work anymore, it still says the firmware is too new?