@ Maroon1;
Pipeline length does not automatically translate directly to the performance. The complexity of the stages also plays a major role.
For example, consider the similar performances of a 2.0Ghz A64 and a 3.2Ghz Pentium 4. The A64 has a 14-stage pipeline, and the P4 a 31-stage pipeline, but the Athlon 64 is not necessarily any faster than the P4.
The Athlon 64 accomplishes this through the use of complex stages and a short pipeline. The Pentium 4 accomplishes the same thing through the use of a longer pipeline, and simpler stages. The effect is that the Athlon 64 can do the same amount of work at slower clockspeeds while the Pentium 4 has to push for higher clocks to compete.
It is true, that at the same clockspeeds, a processor with shorter pipelines and more complex stages will beat out a processor with longer pipes and simpler stages. So, to use your example, if you have a Pentium III at 1.0Ghz, and a Pentium 4 at 1.0Ghz, the Pentium III would indeed beat out the Pentium 4. However, the Pentium 4 was designed with longer pipes and simpler stages so that it could race ahead in clockspeed and beat out the older generation through the use of pure speed.
I'm not sure about how the Willamette and Northwood compare to the Prescott since there are many many other things even besides the simplicity or complexity of the stages that dictates the performance of a processor. But the premise behind the Prescott was to make the pipes even longer, and the stages even simpler, to achieve higher clocks than the older cores could provide. At this point, Intel still hadn't realized the brick wall of insulator leakage that would leave it's processors crippled before even hitting 4Ghz.
Hope that cleared things up a bit (or maybe just made it even more complicated, haha).