It really depends on how much you use it and how you use it. Do you talk a lot? Do you surf? What data apps are running? What apps are running in the background? Are you in a 3G fringe area?
IMHO, there is no real way for us to actually help. I would say you are doing pretty good on battery life. Check the various forums and do a search.
Here is something from the FAQ:
http://www.blackberryfaq.com/index.p...m_Battery_Life