I've had my phone now for two weeks. The first week without 2.1, the second with. I can honestly say that the week with 2.1 has drastically reduced my battery life. For example, my battery is currently about to run out with 6hrs 14 secs since last charged. The usage shows:
Display - 47% (was on the second brightest, not brightest)
Voice Calls - 42% (totaling 53 minutes of voice time)
Cell standby - 4%
Android System - 3%
Phone Idle - 3%
Something tells me this isn't right. My GPS, Bluetooth and Wi-fi are always off too.