I have an itunes account that we will say is email@example.com. I then created a me.com account that is firstname.lastname@example.org. When I created it I thought it would be a good idea to link the two accounts via this web page "https://appleid.apple.com/cgi-bin/WebObjects/MyAppleId.woa/wa/directToSignIn". But now I have a number of iOS devices and reasons for not wanting that @me.com account connected to that itunes account. So I went back to the webpage and removed the added and verfied e-mail account. I then tried to link that @me.com account to another itunes account and it says it is still linked to another account.
So once you have linked a @me.com account to another iTunes account can you un-link it?