I think that plane is just a vision. I remember I seen it in a Discovery document, and they said, that the wide body have a lot of disadvantages: it is very hard to make empty within a short time or it should be equipped only with doors on its side, and the pax far from the axis should have very few comfort because of larger bowing in the corners.
Anyway, you can download a lot of modified, fully-doubledecker 747s, called 797-1000 from FSPLANET. That design makes more sense, but looks ugly. :s