I don't know about everyone else, but for me "released" means I can download it from the official location - http://www.ubuntu.com/download/desktop and that is not the case yet.
I seem to remember that when 12 LTS was released that it was a month or so until you could pull it using do-release-upgrade. Something about wanting to make sure everything was stable before they pushed it that way? It's been awhile so I'm not sure.