While the posted benchmarks may not be authentic, don't be surprised if they're not far from the truth. The only thing close to reputable benchmarks we have so far are the Daily Tech ones and there has already been some serious questioning of their methodology (drivers, MOBO choice, overclocking the 8800 GTX but not the XTX, etc). However, the DailyTech benches only tested DX9 applications. There is some speculation (and for good reason) that the R600 offering will perform better in DX10 applications. If I'm not mistaken, Crysis is a DX10 game and it wouldn't be impossible for an XTX to far out perform the GFX in spite of the fact that the DailyTech benchies paint the GFX as the superiour card. There are also some leaked benchies showing that the XT is far better in Crossfire than the NVIDIA offerings are in SLI. Again, though, there's not enough confirmation of authenticity and testing methodology to make a purchasing decision from. I guess the short point of all this is that we really don't have enough information to determine which GPU is better.
Rob