I would call it 'acceptable'
My typical usage is: wifi/blutooth off. gps/mobile always on.
I unplug it from the PC at 7a. Use it throughout the day syncing with Exchange and Yahoo every 15 mins. Browse a little throughout the day. 20+ sms messages sent/received. Less than 10 mins of voice calls/voice mail. I get back home around 7p and plug it back in. I'm usually at around 50% of battery.
The only time I have run out of battery is when I make more voice calls than normal.