Ars Technica has an interesting post about the future of AMD's desktop processors and Socket AM2:

The combination of AM2 and DDR2 doesn't offer any real advantage for AMD at this point, because their processors aren't yet bottlenecked by memory bandwidth. The introduction of AM2 is a forward-looking move that will become relevant only when more cores per chip and higher clockspeeds start to put more pressure on the memory subsystem. So AM2 isn't going to keep Conroe from retaking the x86 performance crown when it's launched, but then again it's not supposed to. AM2's effects won't be felt until much later in the mid-range, when both Intel and AMD increase the number of cores per socket and memory bandwidth really starts to become a major bottleneck, and sooner at the very high end with four-socket and higher designs.

AMD won't be introducing a major new CPU architecture to replace Hammer until 2007. In the meantime, the company plans to combat Intel's Conroe by exploiting the edge that their combination of a more scalable, glueless multiprocessor interconnect-coherent HyperTransport-with an on-die memory controller gives them over Intel's aging FSB architecture and off-die memory controller.