Based on previous reports about the first tape-out, even if Nvidia would have any working hardware at Comdex, it'd be a first version. So it wouldn't likely be able to run at the final clock speed with final drivers so it's performance would most likely be significantly lower then the Radeon 9700.
It might be running technology demos, and perhaps even a current build of Doom3; although that is unlikely, considering the recent leak of the E3 alpha. But benchmarks are unlikely, as any results on the first hardware would be far below the final revision's capabilities and thus would create a bad impression for the product.