If this should happen ..... WOW! It will be the greatest development in photography for a long time, and both Canon and Nikon will focus on FF DSLRs big time! And why wouldn't Zeiss do it, as everybody knows that the market needs some really good wide angle lenses.
http://www.dpreview.com/news/0512/05122001zeisslenses.asp
http://www.dpreview.com/news/0512/05122001zeisslenses.asp