I got mine on Saturday, and I've actually gotten pretty good battery life out of it. I'm still in the habit of charging it every night, like I had to do with my old WinMo phone, but I think I could probably go two days without a charge. And that's with GPS / data always on, Wifi parts of the day, and pretty heavy use, since I'm always playing with it.
Have you tried something like Advanced Task Killer to keep apps closed that you aren't using? You can also adjust your screen brightness and timeout to try and save power.