There was another comment before questioning the reason that there should be any new R. That's basicly more important than semantics in the German languge.
Other than the S2 being completely out of this world in terms of pricing for amateurs, it would make no sense at all in the current market with flagship FF-SLR's from Nikon, Canon and Sony in the 20-25MP range, to try to gain any share of this pie.
Die-hard fans of the R lenses can use an adaptor for the Canon bodies and be done. The S2 is something new, medium format qualitiy in an almost 35mm size body, supposedly great IQ and convenient handling. What would be the point of difference, not to talk about advantage, of a R10 vs the exisiting rat pack? I don't see that at all.
They should fully focus to get the S2 on the market w/o any hick-ups like the digital R-back. That would prove that they are still cutting edge in camera construction, also in the digital age. Not only producer of exceptional lenses.