Looking at buying a used Macbook Pro, and have seen a few Core Duo models. I know that they can only run 32 bit code, is this going to be a problem with OS 10.6? I realize that 10.5 can run 64 bit code, but I am seeing a larger emphasis on 64 bit in the new OS. I just don't want to buy a computer and have it quickly be outdated. Thanks for any help...