I just got this in an email from Gigabyte, and it looks damn cool.  We are looking at a dual 6600GT card (that’s right, one card) with 256 MB of DDR3 memory on a 256-bit memory bus, running at a memory clock of 600 MHz and a core clock of 500 MHz (each, I assume).  I have included the 1 page PDF file as an image they sent out below.

What is still left to be determined is how exactly this is working!  My first theory is presume that the card itself is splitting the PCIe bus into two buses, one going to each chip seperately and with a direct connection between the two cores replacing the “bridge” that NVIDIA currently uses.  This is the only technically feasible way I can see it working right now, unless the Gigabyte engineers want to complete redo the driver technology which isn’t going to happen.  We’ll have to wait and see.

Gigabyte Previews dual-chip 6600GT SLI Card - Graphics Cards 2