They are iCloud email addresses. Same account, different domain at the end (me is being replaced with iCloud).
I don't know how it works at the moment for creating them, but when iCloud launched you had to specifically choose to use iCloud for email and then pick a username. Simply enabling iCloud for Photostream, Documents, Backup, etc. would not enable iCloud email as Apple would have no idea what username you wanted to use, or if you even wanted iCloud email, unless you chose it. The only thing that would enable iCloud email other than iCloud email itself is if you select to use iCloud to sync Notes, as that uses iCloud email too and makes you go through the set up when you enable it if you've not already set up iCloud email.
If you're sure that you never set iCloud up for email, then have you previously had a MobileMe account? iCloud has been replacing MobileMe.
