You clearly don't know nVidia that well, that's pretty much what they did with the GTX480, and the 470 to a lesser extent. To "save face", the most powerful card is seemingly the most important thing to them. I wouldn't put it past them at all to sell something at a loss just to make sure they're perceived as "the best" by having the fastest graphics card. Even if it's actually slower than the 6990, they'll find some way to declare it as the fastest, be that skewed benchmarks using PhysX, or something completely idiotic.
They are not going to let AMD/ATI beat them on the noise and heat front, they will get something out to take the title