Same as most. Turn on phone, it vibrates, white "Google" logo appears, logo flashes once and the buttons light up, freezes with the white "Google" logo and buttons lit up instead of progressing to the streaming color animation, nothing else happens and I have to remove the battery. This happens from five to fifty times before it boots successfully. I don't think I'm imagining that it's getting worse. Used to take a few tries, now it's hardly ever less than 30. I've basically stopped ever turning the phone off. (I just put it on airplane mode.)
I can still access the bootloader, but rebooting from there makes no difference. This freeze happens regardless of battery level, internal or external temperature, or any of the other bizarre suggestions made above.
I was also a victim of the sleep mode freeze bug fixed with 2.3.4. I had this boot freeze problem a few times prior, probably on 2.3.3, but it's much worse and seems to be worsening.
Anyone with a rooted phone suffering from this? I'm considering giving it a try just to see.
Performance when the phone is finally running seems normal. Although, and this is probably unrelated, GPS functionality in Maps is terrible now. Takes forever to update position, occasionally loses it, updates slowly and often wrongly, etc. Worse than it's ever been on any Android phone and I had a G1 and a Nexus One. Used to be very fast and accurate.