Hello Pelikan,
Welcome to the Leica Forum - Willkommen! If Leica were to stop making SLR cameras and concentrate on making only R lenses with Nikon F lens mounts (as in the case of the "Zeiss" Cosina ZF lenses), IMHO, it would be a tragic error and a major loss for all Leica R users. It would mean that these new "Leica" lenses could no longer be used on our Leica SLR cameras. No, I would not recommend such a strategy.
However! .... About two weeks before the start of this new forum, I went to a Nikon Demo day at a local photo store (I like to keep track of the competition ;-). There were at least six to eight reps from Nikon along with a senior manager from Nikon Canada. I got to try out the D2X (very good ergonomics, excellent AF, but not so great viewfinder..). After some small talk with the senior manager (I have known him for more than 20 years), I asked him about the new
Zeiss ZF lenses with Nikon F (AIS) lens mount. "Doesn't it bother you that a company like Zeiss is coming out with lenses in Nikon F lens mount?" I asked him. His answer was direct: "There was a lawsuit many years ago between Nikon and Sigma, and the judge ruled the lens mount on the camera side is protected, but not the lens mount on the lens side. So if Zeiss wants to make and sell lenses with the Nikon F mount, we don't mind at all". I was so surprised by the answer that I decided to ask him a more specific question: "And what if another company like, say, Leica were to make lenses in Nikon F lens mount?". "It would not bother us one bit", he answered back. So much for the often-suspected legal argument against making Leica lenses in Nikon lens mount.
Curious, I pressed on: "Would you know why Zeiss decided to make those ZF lenses in Nikon lens mount?". The answer was even more surprising. According to him, the creation of the ZF lenses has to do with the movie industry in Hollywood. There is apparently a new trend in Hollywood of using still-picture cameras to create a different kind of "look" to the movies. According to him, the first such use was for the movie "The Matrix" (the first version). The is a scene shot on a rooftop where you see the main character moving in slow motion with bullets flying all around him. The scene was apparently shot with over a dozen synchronized Nikon D1X DSLR cameras on tripods (apparently, there was even a DVD produced that shows the technique). However, the technical staff for the movie apparently noticed that the image quality produced by the D1X+Nikon lenses (AF?) did not match that of the images shot with their film cine-cameras+Zeiss Prime lenses. Specifically, the problems mostly had to do with colors and exposure (and the fact that there was too much quality variation from Nikon lens sample to sample). As time went by, pressure started building on Zeiss (the traditional supplier of cine lenses in the movie industry) to come up with a series of lenses that could be used on Nikon DSLR cameras, but with optical and mechanical characteristics similar to what the movie industry was used to with high-end Zeiss cine lenses (Zeiss Prime and Ultra-Prime lenses).
And that, according to my good friend, is why Zeiss decided to come out with ZF lenses for the Nikon F lens mount. As mentioned by Zeiss since the introduction of their ZM and ZF lenses, the design of these new lenses had been "inspired" by the Zeiss Prime and Ultra-Prime cine lenses. It was all there in black and white in the Zeiss Camera Lens Newsletter
Zeiss Camera Lens Newsletter. While these ZF lenses were designed to be used on all Nikon cameras (film or digital), they were primarily intended to be used on (smaller than FF) digital D1X (and now D2X) DLSR cameras. And as requested by the movie industry, ZF lenses are guaranteed to have matching colours and very accurate diaphragm (set to 1/3 values). And since Zeiss cine lenses are the movie industry standard, it’s one less supplier to worry about for movie producers. BTW, according to a previous Leica forum member who worked in this business, Leica M and R lenses are also used in the movie industry on cine cameras (Arriflex, Panavision, etc..) but are highly modified (focusing mount, lens mount, diaphragm, etc..). Needless to say, these people have big budgets !
To go back to your original question (and to close this really too long post), IMHO, I think that Leica Camera AG should seriously consider making a few of their R lenses available in Nikon F (AIS) lens mount (I would suggest the APO-Summicron-R 90mm Asph, the Vario-Elmarit-R 28-90mm Asph, the APO-Elmarit-R 180mm, and maybe a new 24mm or 28mm R lens). By giving Nikon DLSR camera users a unique opportunity to experience what “Leica Quality” really stands for, by giving them a taste of what they might get with a full system Leica-R camera and lenses, Leica could bring in new customers. And by the way, Leica really does need new customers (hint: we old timers are not getting any younger ;-).
Cheers,
John F.
P.S. I am a realist, and I do think there is a future for the Leica R system. A product that is very different from the Nikons and Canons of the world - a completely different market.