ATI's R600 was supposed to be ready this year, but it seems that some problems were discovered, and the chip won't be ready before nVidia's G80 (although G80 will be delayed as well), and that could mean the latter will have more than 3 months lead start (and that will greatly surpass the most powerful ATI card available, the R580+ Radeon XTX).

The specs of R600 were (at least until now): 65nm technology, 64 Shader pipelines (V4+Scalar), 32 TMU's, 32ROPs, 128 Shader Operations per Cycle, 800 Mhz Core, 103.4 billion shader ops/sec, 512 GFLOPs for the shaders, 2 billion triangles/sec, 25.6 Gpixels/Gtexels/sec, 256-bit, 512MB, 1.8 Ghz GDDR4, 57.6 Gb/sec bandwidth, WGF 2.0 unified Shader.

However, before making holiday plans, you should consider the price of the new cards and maybe you should restrain from buying other hardware. The best thing to do is put it on the list for Santa, as the two boards will probably go over 1000$.