Sony's 1 year warranty is considered short for 1080p projectors. The typical 1080p projector (including the more expensive VPL-VW60) has two years. There are, however several other hi res projectors with one year warranties, and several with three year warranties.
Among the popular competition, the Sanyo Z2000 offers 3 years, the Epson Home Cinema series has 2 years, (with an overnight replacement program for both years). The Panasonic PT-AE2000U comes with a one year warranty standard as well, but when launched, Panasonic was giving away a second year. Mitsubishi offers two years on the HC6000, and one on the HC4900, which, like the Sanyo, sells for less than $2000. Optoma offers two years on their HD80, and one year on the HD803. In addition, JVC offers 2 years on their DLA-RS1 and RS2, Optoma provides three years on the HD81 and HD81-LV, and BenQ provides 1 year on their W5000 and 3 years with a 1st year replacement on their flagship W20000.
Is one year sufficient? I don't think so. Repair of home theater projectors is expensive. Don't be surprised if a major repair is $600, $1000, or more, when out of warranty. The last thing you want is to have your projector fail in year two, and have to write a big check.
In fact, you probably wouldn't. At that point (2nd year), fixing the Sony would mean getting, probably a 90 day warranty on what is repaired, but still having no warranty on th rest. Then consider, by that time, you are probably close to needing a new lamp ($369), and that a year and a half down the road, prices will have eroded, and performance increased on the next generation, so a better projector might well be available for less than $2000.
Get the idea - spend $1000 for a significant repair, still need to spend over $300 for a lamp, or just toss the sucka, and spend less than $2000 for a better projector with a new lamp and new warranty.
While 3rd party warranties are no doubt more hassle than a manufacturer's warranty, they are also far less expensive. I'd have to recommend getting at least one extra year. (Sony sells very expensive extended warranties, if you must have a manufacturer's one.) If however, you plan to keep your Sony for the long run, you might even want to get 2 or 3 years of additional warranty for the couple/few hundred extra it will cost you.