Recent article from cNet on 720p vs. 1080p:
720p vs. 1080p HDTVs: 2009 update | Fully Equipped - CNET Reviews
Just about all programming is filmed in 720p or 1080i as opposed to 1080p. Here's a decent list of who broadcasts in what:
HDTV Listings - HDTV World - CNET.com
I have a 37 inch 720p Sharp Aquos in my bedroom, and it works great. However, when I do replace my TV in the basement, I will go 1080p and get a blu-ray player.