According to the Engadget review...
"...In comparison to the Nexus One, it seemed to fare a bit worse; we could get through a day, but things were down to the wire by the end of the night. It's obvious that a lot of these widgets and background processes HTC is running are going to put a strain on your device, and given that we're pretty active with our smartphones, something is bound to give. Now keep in mind there's nothing really abnormal about the battery life on the Incredible -- it's just not going to wow you...."