[Fittske]

Might want to try a hard reset. I had an issue with "tmail.exe" using up a lot of CPU usage. It was constantly running in the background. After a fresh hard reset, and the disabling of all the background updating crap, I get great battery life. i can usually go from 7AM to about midnight and my battery is usually around 35-40% left. This is a fully day of push exchange email, some sling box, using the phone as an MP3 player for about 2hrs at the gem several phone calls and tons of text messaging.

I recommend you grab one of the free battery monitoring programs, and MemMaid. The Battery monitor will let you know if your battery is draining hat a high rate. Here is what I have observerd when monitoring my battery:
My battery usually idles at around 50-70mA with the back light off.
with back light on no programs running: 130 to 150 mA
with activesync in use (Sending and receiving) 250mA
with MP3's playing (back light off): 250mA
with Opera/sling box running: 325 to 425mA

Hopes this helps.