I don't even think licensing is the main issue. Content (and making money off of it) is the big issue. iTunes could probably be modified to support additional phone types so music and movies aren't that big an issue but the real issue is the app store. Apple makes money on all apps sold (and in-app purchases) and none of those apps would work on an android device (without a WINE type API compatibility) so your talking about Apple creating a second Apple app store with zero existing apps. They'd have to encourage android developers to submit their apps to the google play store and the apple android store. That should sound familiar because that is basically what Amazon does. And you know what, their app selection sucks. No way would Apple ever release a phone that supports the google play store.
Maybe Apple should have pushed web apps a little more... If JavaScript was a "native" development language with true phone hardware APIs then we'd have apps that could enable them to swap the underlying platform without making their app store irrelevant.