I use a 100" inch fixed frame Carada screen and an HD projector in a dedicated theater room, with controlled lighting. I highly recommend them if you have the proper environment. For most 'living rooms' its probably not the best choice due to the relatively poor performance in even normal daytime lighting conditions. Modern projectors with high (actual not advertised) lumens will fair better, but it can't really match most other standard tv's most of the time, and generally even less at the consumer-friendly end.
Lamp life is a combination of care/luck/use. For one you have to careful not to touch the glass during the installation of a lamp, you also have to hope you didn't get a fucking dud, and you can stretch your hours by using the economy mode in most projectors. In a controlled room, that's not really an issue, but you may need to run the lamp in 'high output' mode to make it more usable in less perfect conditions.
Another important factor is the type of screen you are going to use, fixed, pulldown, gray, white, a sheet hung from the wall, reflective paint there are quite a few options, cheap and not so cheap, and they all have ups and downs. Decent screens that look professional are expectantly un-cheap and screen cost needs to be accounted for when shopping for a projector. The cheaper solutions available seem to work just fine, but will not provide the detail of a more expensive option. Also shooting on a blank wall looks like ass.
Keep in mind as well that there are DLP's you can buy in the 65" range for about a grand. Heres a mitsu for 999.00 shipped.
http://www.buy.com/prod/mitsubishi-wd-65c9-65-widescreen-1080p-dlp-hdtv-120hz/q/loc/111/212443538.html