Just to share my battery life result:

I started using my N900 about 3 months ago, current battery life still approx 1day to 1.5days. WIFI is on 24hrs, 3G, average call usage, music and general tweaking around some applications. I don't save on applications and widgets (what's the point of having this great phone when you need to skim on the cool features, right?). I'm not familiar with tweaking the kernel stuffs (though I wish I did) so it's original settings mainly.

But I sure wished the N900 battery could last longer. My 2yrs+ Blackberry Curve 8320 lasts up to 3-4days (with 24hr WIFI, emails and min phone usage)