I bought a Dell Latitude D630 back in early October of '07, and right around the new year the video failed completely. Fortunately, I purchased the notebook with Dell's 3yr Gold warranty and they were out the 2nd day (due to the holiday) to replace it with a refurbished board..... except that the refurbished board failed immediately. Once more the tech was out and this time I lasted until April--I was working on a job out of town when suddenly the video failed again. Fortunately for me (and thanks to the Gold support) I was up and running again the next morning.
I'm seeing a 4 month cycle here, which means I'd be due to fail again in August. I've upgraded to the new BIOS but as everyone else has noted, I'd imagine that's just a small band-aid-fix for a huge problem.
I don't know what I would have done without Dell's warranty. I had to replace another motherboard for an older Dell that was outside of warranty (unrelated problem) and it wasn't cheap. But even a great warranty can't make up for the fact that defective parts cause downtime.
I for one hope Dell/nVidia will do the right thing. This deserves a recall or a part swap of some sort at the very least. Even with a next-day-on-site warranty replacement, one day of down-time can be devastating in the middle of a large project.
Seth