> Update only when you need to update. Otherwise you may alienate your core customers.

This is a bad side-effect of App Store policies. Why is there no auto-update option? Users should be able to go into a settings page and check "let this application auto-update". With an opt-in system like this, users can always have up-to-date versions of programs they know and trust without being bothered to update manually.

This is the way Android does it and it makes tons of sense to me. Just as users are not expected to use File -> Save anymore with something like iOS, they shouldn't be expected to keep track of the version numbers of the Apps they've downloaded, decide on updates, etc.