This is what I did to resolve the iCloud ghost device. I received my new iPhone 6 this Friday November 28th 2014.
1. I set it up as a new iPhone updated (changed) and confirmed my iCloud Keychain security code.
2. I went to https://supportprofile.apple.com/ and verified the ghost device was not listed.
3. I went to https://appleid.apple.com/account/manage/security and confirmed the device was not listed as a Trusted device.

Of course, if you didn't trust any device none will be listed.
4. Since I also have my photos backup with Google+ and OneDrive I deleted the previous phone iCloud backup. You can also download them all to your phone and back them up in the new iPhone identity.
I believe that was all the steps I performed. I am not sure which one fixed the problem, but when I looked this morning the ghost device was gone.
In other words remove any reference of the old device from any and all possible places that it could have created a references. If I remember any other step I will come back and update this post.