Conclusions
The days of scaling performance on single core processor is nearly at the end and the focus of dual core processors are not nearly as much about multithreaded performance as it is about the continuation of Moore's law; that is the doubling of transistors and the doubling of performance. While multithreaded performance will be a major selling point on the workstation and server front, it is less so on the consumer desktop front although I'm sure that the average consumer will be thrilled to be able to do other things effectively while running a task that is system intensive. Multi-core processing will gain in importance as the PC serves a more general role, especially if the vision of the PC being the digital hub at home is realized.
Presently though, it is because of realities on the engineering and physics front that is pushing processor manufacturers in this direction and AMD laid out these issues succinctly at WinHEC. Dual core is here and will be here for the long run because of the inability to continue on the frenzied climb in clock rate.