The BenQ W6000 has only a 1 year warranty
Sony VPL-HW15 - also a 2 year warranty without extra frills
Mitsubishi HC6800 and HC7000: also a standard 2 years
Sanyo offers 3 years parts and labor on their competitive projectors, but, it must be noted, unlike other brands, Sanyo doesn't replace initially defective projectors (DOAs). They repair them instead, and they guaranty no more than 72 hours at their location for any warranty repair.
That gives you a pretty good idea of the competition
As I said to begin with - a good warranty. Just not anything special to write home about!