It's 2006. There's a lot of product shipping right now in the HDTV market, and a bunch of people who are buying in early are going to be unhappy.
1080p is the full HDTV resolution that is supported by BluRay and HD-DVD. It looks totally awesome. It is supported on the PS3, since it's BluRay compatible.
One of the amazing things about the pace of tech progress is that often times the next generation of product will arrive at the same price point as the previous generation. Right now you can get a generous 42" 1080p monitor with HDMI and/or DVI input for under $1500. That's actually less than many of the 720p or 1080i monitors I've seen at the same size.
Early adopters usually expect to bear the brunt of the costs for new tech, but now that the 1080p monitors are available many of them will choose to upgrade from their previous 720p LCD or plasma selections. Someone who's considering getting one now shouldn't consider getting the lower resolution because they'll only have to upgrade later and pay the same price twice.