Awesome responses! Looks like I'll go the 6600 route (with a Gigabyte 965P-S3 and the Corsair XMS2pro 6400). If the extra cache will help with the video, the extra 50 bucks will have been well spent.
Fry's has the 6600 at $297 with free shipping, and it is not listed as a sale price. There are no sale dates, so I hope that means that they have dropped the price down there for good -- until further reductions. The 6400 is 220 before tax, and I did see it on Newegg with free shipping. I can wait no longer than the middle of February, so we'll see what happens between now and then -- although, supposedly, the 6600 will be dropping to the 230-240 range in the spring [this may be just a rumor]. Thanks for the heads up, and keep your eyes on those price drops!
edit: Cali pays sales tax through Fry's. Booooo! I should have remembered this, because I got the hardrive for this system from them (300gb SATA Maxtor). If Newegg has no tax for CA orders of this CPU, the prices are almost exactly the same.