MobileMe has been announced in WWDC, and it will be available very soon. MobileMe uses a brand new domain name “me.com”. Old .Mac users email will be transferred to MobileMe very soon. That is, if you are using username@mac.com, you can now also use username@me.com as the email address. Some users may found it is not working, since it takes time for the complete transition.

[via MacRumors]