Doubt it. Most game developers have not even figured out how to use more than 2GB of main memory or more than one core. I can't even think of a game that currently uses four cores. The next gen consoles have four, and thus that will be the norm for PC games as well for the next six to nine years.
Total War series has been using four cores for a number of years and I'm sure it's not the only game developed for the PC that does so.