Optoma's warranty on the EP1690 is two years parts and labor - simply put, very average in an industry whos projector warranties run the gamut from 1 year parts and labor, to 3 years parts and labor with a warranty or replacement program.
Optoma does not offer a replacement or loaner program, as do some other manufacturers such as Epson, Panasonic and Mitsubishi. On the other hand, it has a longer warranty than provided by InFocus or Dell, who both provide one year standard.
Optoma, from my experience has had a better than average record for reliability. As the former owner of an online A/V projector reseller we sold many hundreds of Optomas a year, and found them to rarely have DOA problems, or failures in the field. (Again, that's my own personal experience - not exactly a scientific study.)