From some latest information we got hold. NVIDIA will have an intermediate chipset before MCP78 series. This series, known as MCP72 will come in two flavours, MCP72XE and MCP72P, both are DX10 and comes with integrated graphics.
MCP72XE supports the AM2+ with HT 3.0., Dual DDR2-800*4, Dual 16x SLI, SATA II, 8ch HD Audio, Dual GbLAN and a Physics slot and Hybrid SLI.
MCP72P supports AM2+ with HT 3.0., Dual 8x SLI, DDR2-800*4, S-ATA II, 8ch HD Audio, GbE, and hybrid SLI.
Hybrid SLI allows the shader processors embedded within the video core to be used in conjunction with an external VGA card to enhance the VGA performance. Yes, the chipset is DX10.