I am sure it is not this simple, but I thought I'd ask anyway. I just upgraded my old C2D 2.8ghz MBP to a 2.3i7 model. My old MBP is running Lion and the like, just like my new one. The only difference is my old one has a 7200rpm drive as opposed to a 5400rpm drive in the new one. Could I simply swap out the HDs before I sell my old machine? Or will the old HD lack the graphic drivers to run as is on the new MBP? I read a case where someone had to clone a drive and then reimage it etc. I'm not sure all of that is worth it, although I don't know how upgrading the HD will effect this new machine. It may be worth it.