In my case, yesterday night I posted here my first impressions. I was at 80% at 11pm, or so (allright, my device, not me ).
I posted via Opera Mobile on the N900. It dropped to 77% or so in 10 minutes. At 12 (maybe later) my device showed a 68% or so when I went to sleep. Maybe something in my web browsing caused it. As carlon said, those of you who don't see any improvements watch your processes and try to leave the phone untouched (the most you can) just to check if battery lasts longer. If you get this, then you could test different usages or just assume that the way you use the phone drains battery.
I don't see anything more that can be said here.