To put it bluntly... if you want the battery to last, don't use the phone. Seriously. From what I've seen thus far, the screen is the biggest killer of them all. That huge, brilliant screen. I have mine set at auto brightness with a 30 second timeout.
Basically, when I use the crap outta the phone doing stuff, browsing, playing Angry Birds I can kill the battery by mid-afternoon. It leave the charger around 7:30AM. Now that I have all my apps loaded and I'm trying to settle into a "normal" phone day I expect it to make it through the work day. It's just before noon and I'm at 79%, 4:15 hrs:mins off the charger. Display has consumed 59% of that, with maps coming in second at 13% as I used it a bit this morning.
Today is by far the best, but again, it's only due to the fact I've only used it to respond to a few texts, read a few e-mails and downloaded one notes program and banged out a quick note.
It's as simple as "using the phone = killing the battery".
PS - I always have everything on... WiFi, GPS, Bluetooth. I refuse to shut stuff off to save a few minutes of battery. That's BS... "oh, I better turn that on so I can use xyz". They should always be ready when I need them and power down when not in use. It's called power management HTC, get on it. I always left everything on with my Torch, and rocked out an entire heavy day of use with at least 50% left to spare. My hope is to rock out an entire work day, charge on my 30 minute commute home, and have it last until bedtime. We'll see how it goes...