The reason it looks so familiar is Rutan built SpaceShipOne, the ship that made the first private suborbital flight, as well as its http://www.blogger.com/img/blank.gifmothership, WhiteKnightOne and the follow on versions for Virgin Galactic: WhiteKnightTwo and SpaceShipTwo. Of course it will not be a sole effort either, SpaceX will be providing support in the way of boosters for the payload.
Here is a short animated film showing how the Stratolaunch System will work.
complete Gizmodo article here
