Theoretical Question – No CPU speed limit

I recently read an article in the September Wired magazine on the creation of synthetic diamonds. If I understand the article correctly two companies are currently producing diamonds in the lab.

The ultimate goal of one company is to replace the silicon in chips with diamond. The benefit is that diamond chips would have an extreem tolerance for heat.

My question is, would there be any point in developing more sophisticated CPU’s if you can take Pentium I technology and clock it up 10 to 100 times? If you can take Pentium I technology and make it work reliably at 50 or 100 GHz what would be the point in using more complex chips?