Apple has placed the official "This service is temporarily unavailable" on the www.mac.com site.
We're still receiving emails at our .Mac email accounts and our @me.com email account has been live since last week.
It's only a matter of time now. Bring on MobileMe!
Links:
[1] http://www.maclife.com/user/rbaldwin
[2] http://www.maclife.com/article/news/adios_mac
[3] http://www.maclife.com/article/news/mobileme_email_address_live
[4] http://www.apple.com/mobileme/
[5] http://www.maclife.com/article/mobileme_goodbye_mac_hello_usefulness