There are newer Nvidia cards coming out including the 7800 GTX I believe which will blow the X850 XT out of the water. Infact the X850 I believe won't stand a single chance.
"Possible specs 7800GTX:
_0.11 micron process TSMC
_430Mhz core / 1.4GHz 256MB GDDR3 memory
_256-bit memory interface
_38.4GB/s memory bandwidth
_10.32Bps Fill Rate
_860M vertices/second
_24 pixels per clock
_400MHz RAMDACs
_NVIDIA CineFX 4.0 engine
_Intellisample 4.0 technology
_64-bit FP texture filtering & blending
_NVIDIA SLI Ready (7800 GTX only)
_DX 9.0 / SM 3.0 & OpenGL 2.0 supported
_G70 comes with 3 models; GTX, GT and Standard
_Single card requires min. 400W PSU with 12V rating of 26A
_SLI configuration requires min. 500W PSU with 12V rating of 34A
_Launch : 22nd of June"
http://www.pcunleash.com/bbs/zboard.php?id=PerformanceBenchmark&no=1565
The specifications on this new card, that is going to be released shortly, is just plain insane.