If your talking about you're core 2 duo, you really shouldn't have a problem seeing as how you have it pared to an Nvidia 8800 which should be kicking for at least another 2 years depending on how much you love eye candy. If I was you I would wait ill about February or march depending on the Intel market, and jump on a Q6600 (because if they are in the 200+ range right now in Jan they could be in the 150 area), if you don't want to upgrade your mobo that is the best option. Because the new Intel processors I hear are not compatible with the 775 socket and therefore would be incompatible with your mobo.
(Almost forgot the Q6700 (I believe its called) could also be another option or one of the Extreme Quad Core 2 Duos could probably another option in about 4-6 months, if you could find one by then)