DRM in the chip
One aspect of this transition that could prove interesting, in all positive and negative connotations of the word, is the so-called "trusted computing" capabilities of Intel's CPUs. Little has been done with them yet, but as we understand these capabilities, they're designed to work with a Microsoft digital rights management (DRM) system. There's no telling if or how they may play into Apple's existing music or future video plans.
TidBITS points out an underexamined factor in the Apple/Intel announcement.