the dual core will not only be good for gaming
They aren't really good for gaming. They aren't bad at it by any means, but they dont like...excel at it better than a normal single core CPU. You could simply burn a DVD while playing a game without losing and FPS though. BUT, of course in the future games will take advantage of dual cores and be multithreaded and then it will be an improvement.
One thing to realize with dual cores that I just realized today myself, is that you will need to do some hotfixes so that it works 100% efficiently. Theres issues in games without the hotfixes. Seems annoying, but I guess in the end it'll be worth it. You'd just have to do it everytime you formatted your computer as well.