Due to the number of problems I've been having with my new MBP, I'm anticipating that I will be getting a replacement. I've had numerous calls with the Apple Expert line and still haven't been able to resolve my issues. If they do decide to replace it (it's only about 6 weeks old) would it be possible to upgrade if I pay the difference? I have the uMBP 2.66 4GB and would like to go with either the 17" or the 15" 2.93.