According to a comment below, "[The animation is] not affiliated with the film, leaked or in an official capacity. It was created by a small business of 2 men who are trying to gloss up their resume and get on board with Wild Card Media. They posted this to Vimeo four days ago. It has since been removed for using Warner Brothers's marks for business (commercial) purposes."
A brief, new video purporting to be a produced-but-not-yet-released look at the Man of Steel logo reveal seems to have gained consensus as likely to be real, and possibly attached to an upcoming trailer. You can check it out below--about twenty seconds of CG words and pictures with no new footage from the film, but certainly with a sense for tone.
With The Hobbit coming to theaters soon, it's likely that Warner Brothers and Legendary will attach another Man of Steel trailer to that film--it's likely the last true blockbuster the studios are releasing before the Man of Steel campaign kicks into full gear--and according to Bleeding Cool, the YouTube user who posted this video lives in an area that puts him proximate to post-production facilities and often posts items like this which turn out to be real.
BC speculates that this particular footage is probably not part of the trailer, but both they and other sites have concluded that it's likely something put together by Warner for promotional purposes of some kind or another.
Check it out below and let us know what you think.