Given AMD's failed attempt at a desktop comeback with the Phenom, and Phenom II's impressive but not show-stopping performance, their next few moves have been anticipated by many. John Fruehe, Director of Business Development for AMD, recently solicited and answered several questions about what they have in store. Although particularly referring to workstation and servers, an area they have a good reputation in, their moves here may give a hint on what's in store for desktops in the future.
The biggest piece of information shared was that their upcoming C32 socket will not be backwards compatible with socket F. This means no easy upgrade path for Opteron servers. AMD will diverge even further from a homogeneous setup with the G34 socket - Opterons for G34 and C32 will be mutually exclusive, with 4/6 core CPUs aimed at C32 and 8/12 core CPUs aimed at G34. They also mentioned their intention to be chipset suppliers for these new processors, but aren't excluding other vendors from making their own.
Fruehe mentioned that there are concerns about software scalability for handling multiple cores, with AMD planning a rough ceiling of about 48 cores on G34 systems. According to him, the high-thread market will have a hard time finding a practical use for single systems that have massive number of cores (think nearly 100 or more), at least for now. It seems AMD is betting on cloud computing and developments such as the HyperTransport HNC specification for scalability rather than on adding more cores to a machine.