Dear Original Poster,
The answer at this time is NO. A big fat NO. Courtesy of Apple.
When you go to the iCloud.com website, it is possible to change your Apple ID, however Apple clearly states that there are 3 restrictions/requirements for you to choose a
new Apple ID:
1) Apple ID must be a valid email address
2) Must not be an email address already in use (by someone else)
3)
Apple ID must NOT use a domain owned by Apple
#3 is the big doozy. Someone at Apple needs to get slapped in the face for this restriction. The logical thing would be for Apple to *encourage* the use of their own Apple-centric domains for their own Cloud services (icloud.com, me.com, mac.com, apple.com, eworld.com just kidding about eWorld, you all are too young to know what the hell that is....). But apparently, logic has failed Apple in this. Screenshot below.