The Inq reports NVIDIA is still having problems shipping the GeForce 7800 GTX 512MB so they have decided to drop the prices of the 7800 GTX 256MB parts.
Unfortunately, these price cuts will affect Nvidia partners only as we don’t think that any of them will make any drastic cuts. Nvidia was selling GTX 256MB cards for roughly $300 while it will sell the same card for $230, I guess it's to keep them calm as they can not get any 7800 GTX 512 to sell but the demand is there.
This implies that Nvidia has quite a few 7800 GTX 256 MB cards while it's still lacking its much higher clocked 512 MB cards. Nvidia doesn't want to end up with too many 256MB cards as the new G71 is getting awfully close to its birth.
With the GeForce 7800 GTX 512MB, NVIDIA did made the cards available on launch but unfortunately most cards were already sold out on the first day. The Inq makes an interesting observation:
What is better? To do the hard launch and to be unavailable for the rest of time, or to press launch and promise the cards later, and once they became available, they stay available?