At a glance, in horizontal mode it seems to work, not so in vertical for now, which could be a doodle to change.
photo 2 | Flickr - Photo Sharing!
The possibility to use MF lenses on the A7R is very intruiguing to me. If Fotodiox is willing to make a few changes this could turn into a 6x7.
Hell, they just have to make this work!