NVIDIA has silently launched a new GeForce 6600GT PCI Express with 256MB memory. If you wondering why it comes so late here's an explanation from The Inq, it is related to Doom 3.
It didn't take long for nVidia to realise that two 256MB 6600GTs in SLI could give the 6800 Ultra a run for its money in Doom 3. And two 256MB 6600GTs cost about 30% less at the time. The solution was simple: kill the 256MB version and only sell a 128MB version. That way the cards were hobbled and couldn't interfere with sales of the top end Ultra.