Nvidia's original plan was to price the D8P/G92 at $ / €299, but ATI’s aggressive pricing changed Nvidia’s mind. All the early adopters of 8800GT have to thank ATI for the $249 and $199 prices for these cards at launch.
We can now confirm that Geforce 8800GT will win against RV670XT, clocked at 825MHz with the DDR4 memory at 2400MHz. Nvidia’s chip is more powerful and faster in most of the games and synthetic benchmarks; but, at the same time, the chip generates more heat, it's 65 nanometer and it is more expensive for Nvidia to make.
As a consumer you don't need to worry about these things; but knowing how the new ATI thinks, we can bet that RV670XT / PRO and GT will end up lower priced than Nvidia prices and this will be their way to fight Nvidia.
We also expect that ATI will make a big deal with its 55 nanometer support, but we expect that a lot of the press will burn ATI for the HD 3xx0 names if they decide to go down that path.