I believe that such a bike does exist in the form of the Pacy 26 inch wheel dual-suspension folding bike made in Germany. Please see the following Web pages:-
http://www.pacy.net/p26/index_p26.html - on the Pacy Web site
http://www.kinetics.org.uk/html/pacy.shtml - for the Pacy page on the Kinetics Web site
I have tried out the Pacy demonstrator that Kinetics have at the moment. This particular example has full front suspension and a elastomer at the rear. It is equipped with derailleur gears. However you can specify different components to suit your own preferences. An example that is currenntly on order for a Kinetics customer will have a Rohloff hub. The Pacy bikes are of a high quality and beautifully finished. Apparently the bikes are hand made to order in a very small workshop - or so I have been told.
Gordon Petrie