It looks like they have quite a few drawbacks, however, the ability to play your games in an immersive cinematic experience is quite tempting. It looks amazing just from screenshot comparisions. In a FPS, which I plan on playing lots of, a wider screen could give you quite an edge in combat.
My main concerns are response times and dead pixels.
I second that on response times. I've been using a Samsung 213T-21.3" LCD for a while now, it's not a widescreen though. Samsung's specs indicate a response time of 25ms, which according to "some people" is just unheard of to try and play a game on. But I have to say, even if the 25ms is accurate I've played q3 online, q4 (single and multi), d3, HL1, HL2+ep1 and I've never had a problem with the monitor not performing in situations.