I don't have any experience with this, but I doubt that Apple would upgrade the computer after you've gotten it. As far as I know, the processors in the MacBook Pros are soldered in, which would be a little bit more difficult to swap out than a RAM upgrade. Maybe it will turn out that they haven't soldered the processors into the 17" MBP's and you'll be able to make the switch, but I wouldn't get my hopes up.