Most games... <ahem>... the vast majority of games only use 2 cores, there are some games that can use 3 cores, fewer still that can actually use 4 cores effectively and maybe 2 or 3 games that can actually use more than 4 cores.
The total numbers of games that can use more than 2 cores is a fraction of the games that only uses up to 2 cores.
There is no confirmation about how many cores will be in "Liverpool" (the codename for AMD's console CPU), but it is possible that it will have 8 cores. How well will console games be capable of utilizing multiple cores? Initially probably not that well since there is a learning curve involved. Fortunately for developers the hardware in consoles are pretty much static until the release of a next generation console. This gives them time to learn.
Will more PC games come out that supports more than 2 cores? Yes, but I think that it will be a very, very long time when the number of games produced every year that can use more than 2 cores will exceed the number of games that can only use 2 cores. Why? CPU processing power continues to increase. A dual core i3 CPU can keep up or surpass a Core 2 Quad CPU in many tasks.