I experienced the exact same issue. Charging would take at least 8 hours, and the phone would be dead within 3 hours. I was running Advanced Task Killer, uninstalled it, and had the same issue. I had not ever started the FB App, but it was running, and I stopped that. I also tried reducing the Exchange sync frequency. Even still, you could practically watch the gauge go down, and the phone was incredibly hot. You could leave it dark for 60 minutes, come back, the phone would still be hot and you'd have lost at least 25% of the battery. It was so bad, it reminded me of my old HTC Titan running WM6.
After backing everything up (Astro File Manager is an easy way for that), I performed a hard reset and data wipe. I did have to re-activate the phone, but since then 2.2 has been running fine, and I am holding a charge as well as ever. Exchange is on push, ATK is still not installed, and everything seems OK. I'm going to slowly go back to playing around with my settings and see if I come across anything else that might have been causing the drain.
The build I am showing is: FRG01B
Hope this helps someone!
After backing everything up (Astro File Manager is an easy way for that), I performed a hard reset and data wipe. I did have to re-activate the phone, but since then 2.2 has been running fine, and I am holding a charge as well as ever. Exchange is on push, ATK is still not installed, and everything seems OK. I'm going to slowly go back to playing around with my settings and see if I come across anything else that might have been causing the drain.
The build I am showing is: FRG01B
Hope this helps someone!