AMD's design makes it very easy to add more cores. They created an internal communication bus for the cores to communicate with each other, rather then some custom n-way signal system like older multi-CPU systems used. This means that adding more cores just means adding a new connection to the bus rather then any custom hardware. Because of this it will be very easy for AMD to add more cores to their systems.

The downside is that the bus has a finite communication rate, which is shared between the cores. At some point AMD will have to either increase the communication rate of the bus or their CPU's will suffer from bandwidth starvation.

In any case, I'm not sure how far multi-core will go on the desktop. From what I have seen even jumping from 2 to 4 cores doesn't provide as much benefit as going from 1 to 2 did.

The benefit will go up as OS's and applications are recoded to take advantage of multiple cores. But there is a limit from how much tasks can be threaded to take advantage of this.

I expect desktops will lag behind servers, and it wouldn't surprise me if it really develops into two distinct chip lines. Server systems built with a large number of cheap core, while desktop systems have fewer but faster cores.

Jay