Really, when it gets down to brass tacks, all these updates are marginal from a gaming perspective. Sure, 45nm is nice, and the added cache is nothing to argue with. Indeed, if someone placed a Q6600 and a Q9450 in front of me, it wouldn't be hard for me to choose between the two. However, realistically speaking, a current generation E or Q processor with a nice OC will last just as long as a Wolfdale/Yorkfield with a nice OC.
If you can wait for the new procs, and don't mind paying a premium for them, then by all means. But, again, we're talking a maximum difference of 1-3 FPS between comparable CPUs from the current generation and the Wolfdale/Yorkfields.