Intel has CONSISTANTLY improved chip performance within the same generation without resorting to such tactics. Remember the Pentium when it got its MMX refresh? OBVIOUSLY software didn't take advantage of MMX immediately, so the chip was just designated "Pentium XXXMhz MMX"
Then the PII got a Procesor ID, and SSE and a minimum FSB of 100Mhz all of a sudden it was a "Pentium III," not a "Performance-Rated PII." It took some time for software to become optimized for SSE, but it has happened. Then the P4 came along with SSE2 and an entire architechture change which is obviously going to run older X86 code less efficiently (because nothing is optimized for it yet). Thanks to AMD pushing CPUs with old software in mind to astronomical clock speeds, the P4 has remained the CPU with unoptimized software and has remained clock-for-clok slower (There's is no magical "IPC" value that was "lowered" for higher P4 clock speeds). People claim software, such as benchmarks, that utilize SSE2 optimizations are "cheating" AMD just because they are moving to the platform that has a higher ceiling for the future. "MMX" benchmarks wern't cheating. I did read that Intel will "not emphasize" megahertz as the performance-selling factor for Banias (Which is highly optimized for Pentium Pro/PII/PIII code), but that does not mean they will invent a new speed measurement. Hyperthreading slows down many unoptimized applications, even many apps designed for dual CPUs! So it's not even considered the P4's MMX, much less something to "performance rate." It will simply be the Northwood-core "Pentium 4 HT." It will even have "HT" on the logo just like the "M" for the mobile part and "MMX" on the old Pentiums.