If you are interested in speculation and analysis of advancing technology, a recent article
at Arstechnica concerning Intel's latest and various core revisions covers just that. One of the primary points, which is interesting in the scope of how CPUs are normally developed, is the current generation of P-M. While P6 architecture (more currently, Pentium III based) is the primary innovation behind Pentium M and a combination of technologies giving us“Core”, all the hype behind the advantages of processors with multiple cores since x86 brought it to the desktop market isn't just hype, as the article brings out.
The Pentium 4's performance was designed to scale primarily with clockspeed increases. In contrast, Core's performance will scale primarily with increases in the number of cores per die (i.e. feature size shrinks) and with the addition of more cache, and secondarily with modest, periodic clockspeed increases.
Core may start to change the way a lot of people see Intel's current lines, and in all areas of the CPU market we're seeing a shift in how performance is defined.