Tom's Hardware has a full review of the next-generation nVidia GeForce card, the 7800 GTX.

nVidia claims that the 7800 GTX has been re-designed from the ground up.  The GTX comes with 256MB of RAM, 24 pixel pipes, and 8 vertex shaders.  With 302 million transistors, the 7800 is the most advanced GPU ever.  Of course, bear in mind, ATI is about to launch their next-gen GPU shortly.  So it'll be interesting to see how the two stack up.