It all depends on what resolution you are going to game at. If it's anything under 1920x1200, your whole system is going to be somewhat bottlenecked. Also, LCD's can only display up to 60FPS at the moment, which a lot of cards can achieve these days.
Intel will be launching their mainstream Nehalem parts soon, called Core i5 and running on socket LGA 1155. This will also use DDR3 ram, but in a dual channel set up rather than the triple channel version in Core i7. Core i7 will actually possibly last longer then i5, read up at Anandtech this morning about that. Although Core i7 is still very expensive, it's a system that won't exactly be slow overnight.
