What MSFT absolutely nails in this arena is the experience in the XBL marketplace. If you buy something, it's yours forever (well, longer than in the app store, anyway). Many many games have been pulled, usually because the owner of the game has gone out of business, but if you've bought that game you can go and download it again at any time. Device licensing is also straightforward, whereas if I sync apps purchased under different apple ids to my iPhone I can get really bizarre behavior with on-phone updates and app-purchasing (sometimes it changes who it thinks I am, depending on some combination of who's app I synced/updated last, or something).
It's something that I wish I could to in the App Store. I need to keep tabs on my IPAs in case there's an app that I bought that is no longer available. In this day and age I shouldn't need to do that.
Apple's implementation of this category of stuff feels really rough.