This is for those that have an old .Mac or MobileMe email that has been granfathered into the your iCloud account
I am just doing a check. I still use my .Mac email to sign into my accounts and it associates with my MobileMe and iCloud emails as well sine its all one account. I have noticed in the beta that I can still sign in with all 3 emails onto icloud and appleid and send & receive with all 3. however.... the MobileMe has disappeared from the iMeassges account and FaceTime account so I can no longer be reached at that MobileMe email. I am only able to be reached at by my number or the .Mac or iCloud version of the Account. After torubleshooting with several devices and going through all the steps to restore all 3 emails ot the account MobileMe is still unavailable. I say that to ask this. Can others check to see if you see your MobileMe email is showing up in the Messages preferences on your Mac or iOS device.?