I've just been doing the mental math to see what I'd leave behind if I just started using my email@example.com MobileMe ID (converted to an iCloud account) for family iTunes purchases and my new iCloud formalname@me ID for the Mac App Store, primary email, calendar sync, etc. I'd really like to -- once and for all -- ditch my original @yahoo.com email that I used to use for my Apple ID. What would this affect beside old Apple.com online purchase history (hardware like Macs, iPods, etc.) and an inability to redownload the iTunes tracks bought under the older @yahoo.com based account? The balance on my existing iTunes account can easily have purchases "gifted" to the new iTunes @me.com account, and any existing iTunes Plus/AAC music should be easy to import in iTunes. I've been putting off a number of online purchases including the upgrade to Lion, some additional MAS purchases, and even some iTunes movie content for my kids until I get this figured out. Am I overlooking anything obvious?