Retail motherboards are expected in November and it's anticipated that these chipsets will be great stuff for overclockers.
C55+MCP55 sports SLI x16 with a total of 50 PCIe lanes in 22/4 + 28/6 configs. It supports DDR2 800, 1333FSB, 6 x SATA2, dual GbE, HT 1.0, 10 USB, HD-Audio.