AM2+ isn't even out the door yet, & AMD's got AM3 on its mind. The difference? DDR3 support, of course. Now if only DDR3 would start coming down in price...

"The initial reference boards that support AM3 processors will be based on an AMD RS780 northbridge and an AMD SB700 southbridge. The northbridge and southbridge communicate with each other via a 4X PCIe lane. The northbridge communicates directly with the CPU using a HyperTransport link."