Honestly trotter, i think your estimate of a few years is way off. The reason i think so is that games for the next generatoin consoles are already being designed to utilize multicore processors. This will surely prompt PC game makers to follow suit to compete with the ever shrinking market share that PC-Games consume. Console games out sell PC games by far. These new consoles, by their specs. pack a hellava punch. Have you been into an ebgames lately? Over the last 2 years the PC-Game display has grown smaller and smaller. Now, each store has may-be 1 or 2 displays. Also is true for many other video game stores. Where now console game shelves have double for all consoles.
The Unreal Engine 3 is being designed to work for both PC games & Console games. Which means that for console games it must support multicore processing. I expect that it will be supported in PC's as well. Now this has yet to be confirmed, but doesn't it make sense? AMD is known for it's 64 series being "gamer" oriented. With their latest release of the X2 series, would you think that the accompaning game developers that are in AMD's pocket would start developing games to drive the sales of their Dual Cores? I think it makes sense.
All of the benchmarks prove that the the X2 4800+ outperforms every processor on the market in multitasking / multimedia processing. Intel doesn't even have a chance against it. But, the AMD 64 series is market is driven by gamers. If games start supporting the Dual Core processors and can prove to be better then the single core, they will start flying off the shelves.
Now i might be jumping the gun here, but I believe what i've said makes sense. Dual Core support in games is coming sooner then you think.
If i'm wrong, it wouldn't be the first time and probably not the last.
Here's an article that supports my assumption: