I plan on building a system but am unsure of which CPU.. I'll mainly use it for gaming so i'm thinking about going with the E6750 for now, overclocking it, and then upgrading to a quad core once the 45nm's come out in january.. or will the performance increase not be that much from the current Q6600?

Most games will not take advantage of a Quad Core CPU. I don't think you will see much performance difference between a Dual Core and Quad Core CPU at the same clockspeed for a couple of years. But I could be wrong.

If you were to do video encoding, then I would say Penryn and Quad Core all the way.

i'm also wondering what the performance will be like from the Core 2 Duo 8000 series..

A bit more than the 6000 series but running cooler. Or were the 8000 series replacing the 4000 series? I can't remember.

The quad core 45nm's not being launched next week?

Only the extreme version. $999 at least. Non-extreme versions will launch Jan-March 08.

If you are thinking of Upgrading in Q '01, Go with something like the E2160 and OC it to about 3.2-3.4 Ghz.

Then in Q 01' grab one of the new Quads.

The new chips should be about 5-10% faster clock for clock, but they should also be able to OC perhaps another 10-15% higher yielding maybe a 25% boost total when all is said and done.

But waiting all depends on what you have now and what you want to do.

The 8800GTS should also be out soon and heck perhaps a new 8800GTX by then as well, even though I have not heard such rumors yet.