Just got off an hour call with Apple Support and they could not resolve the following issue:
My original Apple ID is my @mac.com email address, which is tied to my MobileMe subscription that has expired and was not renewed. Therefore I wanted to change my Apple ID, as is make no sense to have an ID that is an email address that is no longer used or could be used by another person in the future, even if I can still change the "Email" to another address. However, Apple does not allow the Apple ID to be changed because it is tied to a MobileMe account and will tell you so when you go to myinfo.apple.com. So, I created a new Apple ID which is not linked and can be changed at any time. BUT the problem is that I have to log in the old account to update my app purchases as that is where the purchase history is stored. Basically, I'll have to log into two accounts for the rest of my life to update all my apps. Very poor user experience. So would recommend against using your MobileMe email as your Apple ID unless you intend to keep it forever.
My original Apple ID is my @mac.com email address, which is tied to my MobileMe subscription that has expired and was not renewed. Therefore I wanted to change my Apple ID, as is make no sense to have an ID that is an email address that is no longer used or could be used by another person in the future, even if I can still change the "Email" to another address. However, Apple does not allow the Apple ID to be changed because it is tied to a MobileMe account and will tell you so when you go to myinfo.apple.com. So, I created a new Apple ID which is not linked and can be changed at any time. BUT the problem is that I have to log in the old account to update my app purchases as that is where the purchase history is stored. Basically, I'll have to log into two accounts for the rest of my life to update all my apps. Very poor user experience. So would recommend against using your MobileMe email as your Apple ID unless you intend to keep it forever.