We found out that at least the big three will have the motherboards based on Nvidia's upcomming MCP 680 chipset. We are sure it will end up with Nforce in the name but we still dont know the final one.
There will be plently of designs based on this chipset and this board is a direct competitor to ATI / AMD's 690 chipset. It will be fun to compare the integrated graphics on Vista. This is not all Intel plans to unveil its G33 motherboards with a new graphic core and new DDR3 memory support.
We will work to get more of the specifications but all boards should have very similar features. You can read more about the chipset here.