nVidia just released the GTX 285, which is basically a die shrunk and optmized version of the GTX 280. They went from a 65nm to 55nm chip, reducing power consumption and heat dissipation. Performance-wise is about on-par with a gtx-280 but, since it runs with less power and heat, more able to be overclocked.
Review: http://hothardware.com/Articles/NVIDIA- ... -Unveiled/
So if you were thinking of buying a gtx 280, don't!
Price is actually higher than for a gtx280, but that's likely to change in the near future.