Battery Life
It's decent. I didn't even check the reviews, I just went ahead and bought the Droid Incredible, and on the first day I was just like WTF IS THIS with the battery life. But then after a few weeks I got some battery saving apps and it works a lot better now. Currently...
I can run like 5 hours of sustained heavy use. This includes live wallpaper, adw launcher, multiple applications, constant button pressing...(you get the point) with my droid incredible. I do recommend a bigger battery however, simply because the stock battery isn't that good. I'm using the stock one, but usually i won't use it for like 4 hours straight so it's fine for me.
A droid incredible should be able to last you a day. It lasts for me from 6 AM to 9 PM no problems, with roughly 4 hrs. of usage in between.
BTW: If you do get the Droid Incredible I recommend getting setcpu and underclocking the system. The Droid Incredible just performs at a much higher rate than it needs to...by underclocking the phone my battery ended up lasting for a much longer time. Just check the other threads, there's a bunch of tricks for extending the battery life. If you purchase a Seidio 3500 battery then you'll never have any problems with battery.

Hope I helped, sorry I rambled, dancedroid!