Well, a Sanyo PLV-70, at 1280x720 and 2000 lumens, can easily project a watchable image in full daylight, and it can be had for around $5000 US. Couple that with a high-gain (2.0 or higher) screen, and you have a 100" projected image at half the price of the Mits 82" and sunglass-inducing brightness!
But, 1080p resolution is nice. Now, where are the 1920x1080p LCOS front projectors?
The one thing going for the Mits would be bulb life...if it is anything like the Samsung DLP RPTVs, I'd expect at least 10,000 hours of useable bulb life (like CRT tubes).
Yes, you can certainly get great brightness and quality for cheaper in the FP. But don't you lose blacks? IE the darkest that the screen gets is the ambient light in your room. I was at a somewhat dark sports bar last week with 4 projectors next to each other, and you could always see details missing compared to the regular tv's.