True, but finally intel have learned that AMD kick back, unlike P4 where they kept issuing refresh after refresh, Intel appear to be planning ahead properly, with a roadmap which basically alternates between process refresh, and new architectures.
So with Core 2, we'll see a process update to 45nm(2007), then a architechture update in 2008. And they appear to be planning a 32nm processess in 2009, and then yet another new architecture. And dont forget intel are still using a traditional FSB on their processors. So they still have the potential to improve performance further by integrating the memory controller. They also have CSI to counter Hyper Transport, and they can still bring Hyperthreading back into play as well. With Core 2 being a 4 issue core, it should in theory be better at Hyperthreading that P4 was. (Hyperthreading mearly allows a second thread to utilise unused parts of the cpu core. The wider the core, the more chances of ports going unused)
I think AMD will kick back, but Intel are now on their toes, they realise AMD is a serious player, and dont want to be caught with their pants down a second time.
Sun Microsystems have a quad core processor, which is capable of a system similar to hyperthreading, which allows each processor core to run up to 8 threads concurrently, of course thats a workstation/server platform. However imagine the potential of a desktop PC with a Core 3 Quad, with hyperthreading enabled, CSI, and an integrated memory controller.
Of course thats purely speculation. Intel are claiming 80 cores in the future, I wonder if thats a combination of physical cores, and hyperthreading though.
Just remember the same logic can be applied to Intel as well. Both solutions are mulitple discrete processors glued together with various lightweight methods. Arguably Intel's cache-sharing is the better design due to the way multiple processors are used in an OS.