Username or EmailPassword
The entire iTunes music store is an exercise in monopoly abuse. Would the iTunes music store have been popular if the iPod wasn't the dominant player when it was created? Would the iPod/iPhone be so dominant without the iTunes music store exclusivity? Apple leveraged their dominant position in the music player market to become the dominant music store. Then, Apple used their dominant music store to further block competitors from the music player market (enforced by fairplay copy protection). Now, they are using the music store to further expand into cellphones and PDAs.
The obvious solution is that the iTunes media store should be separated from Apple and be available to other players through openly licensed interfaces (not necessarily through iTunes software). However, it remains to be seen whether the US gov't will enforce antitrust laws again.
Now, with that said, this back-and-forth blocking/unblocking doesn't work well for Palm customers. Palm should have known that Apple would block them and had a backup option available from the start (probably using the supported XML files for syncing).