Gigabyte do 7900 GTX SLI on Socket AMD
Also on Gigabyte's stand you'll see their Socket AM2 test board running 7900 GTX SLI. The board runs DDR2 memory, but like many of the vendors showing off AM2, they refuse to disclose the CPU being used to power the demo system.Gigabyte hinted that it was an Athlon X2 of some decription, but that's all the details they were happy to give up.
7900 GTX SLI running on MCP55 with Socket AM2 seems to be the demo combination on display at this CeBit, so I'm sure you'll see more shots of similar systems from us as the show goes on.