The Sharp XV-Z30000 projector definitely comes with a better than most warranty. Not the best out there, but longer than most.
The Sharp XV-Z30000 comes with a three year limited parts and labor warranty.
This projector lists for $4995, but sells typically for a significant discount. Most projectors in the $3000 to $5000 price range offer 2 years. There are a few three year warranties including this Sharp. There are (surprising but true, also more than a couple of home theater projectors with only a single year warranty.
A three year warranty is pretty great. I can't think of a true longer warranty (rather than some gimmick like warrantying the DLP chip for 10,000 hours). The only thing out there that's truly better, is a three year warranty, with some replacement program. I can only think of the competing Epson 6010 (available only from local dealers) as having 3 years and a 3 years replacement program. Other than that projector though, I can only think of a couple of 3 year warranties with 1 year replacement. Some of you might prefer a 2 year warranty with two years of replacement (that's Epson on Home Cinema models - they are really the main player in replacement for the home projector market. By comparision replacement programs are far more common on business projectors).
Ultimately though, that means, by my reckoning, that there really is only one home theater projector out there in the $3K - $5K with a better warranty. In this case second best is really really good! Kudos to Sharp for a longer than typical warranty, one longer than many projectors selling for up to twice the price.