Well, as mentioned in that Q&A you linked to, the UE3 does gain some small benefit from more than 2 cores. Crysis, another major title released within a few weeks, is supposed to benefit greatly from more than 2 cores. Valve's next version of the Source Engine is also being developed to benefit greatly from more than 2 cores.
These are all games/engines of this year, and many other games will be using these engines as a base. That's why I think that already next year we'll see most games supporting, to some degree, more than 2 cores.
Already there's a few games like Supreme Commander that takes very good advantage of quad core.
Interestingly, the 2.4ghz quad core actually outperformed a *4ghz* dual core in the game Lost Planet(
Link). That's some good developing.
Again note that I do not actually support buying a quad core before the next generation of them appears within the next few months, though. Then we'll probably see much better cooling, power consumption, etc.