The Monochrom is a novel camera and as the only dedicated B&W camera on the market, it is without peer, but then again this is a small niche market. I am very lucky that Leica built a camera that suits me well, and to take it a bit further it seems that Leica kinda built me my dream camera.
Leica glass has its own identity and rendering which is another novelty. I can say there is nothing like Leica glass, and it would be true. As suggested by others, Leica could easily invade other makers' turf and make lenses that accomodate the other makers' DSLRs. Never to be a 800 pound gorilla, but it could impose some loss of market share to competitors and make another premium niche market that furthers the Leica brand.
The Nikon DF is a cool camera in concept, but didn't go as far as many would have liked. The most frequent complaint is that the DF has a plastic feel, has too many buttons, and does not offer interchangeable screens. Basically Nikon did not make a camera that was retro enough for many, nor basic enough to be just a stripped down digital color camera with a great sensor, offer no frills and a solid retro vibe, with perhaps the only complexity being interchangeable screens. Pretty much the market research and the focus group work has been done for Leica to create yet another niche camera. How radical and out of the box would it be for Leica to make another SLR again other than the S2 and S. Definitely another niche camera, that would not have mass appeal but it would yet be another boutique camera. This time riffing off a Nikon DF.
If Leica makes glass for other makers' bodies then why not make their own small format SLR again, but digital. Kinda a crazy idea but I like it. In the boutique world something novel is always good.
BTW I still hope MM-240 rumor is true. Not for everyone again, but a very cool camera.
Cal