6-core ASAP
I too am clicking on an order for a BTO 6-core as fast as I can when the online store starts taking orders, and I too will do so even if it's priced with diabolical evil, as I expect it will be. I just hope they don't get so backed up in China with 6-core MP orders that it takes weeks to ship.
I have my vanishing last-of-its-kind developer discount to apply...it expires in December and they ain't selling them any more. It's worth $500 off the current MP. If they make it worth less (or make it worthless) on the new ones, I'll make my displeasure known, but I don't see they have any reason to do that (even though I was somewhat surprised to see that the developer discount was $0 on the iPad, which was not released until after Apple had stopped selling developer memberships to the public).
Then I'll pull the cards and extra drives out of my venerable (but fully operational) early 2006 MP 1,1 and recycle it for however many gift-card pennies Apple's junk dealer will give me for it. It's not worth hassling with ebay.