Wow, fascinating rumor. I love the part where they note that Sony understand that niche markets are profitable - I consider myself an extreme niche sort of shooter and they certainly scratched my itchy niche with the RX1.
I can't see buying a dedicated B&W camera, though. I just like using color channels in B&W processing too much and I haven't seen anything from the Leica M that convinces me that the end results are better enough to be worth a dedicated sensor. Plus, I'm often surprised how many shots I'd inteded for B&W end up coming to life more in color (and vice versa), so I guess I just like to keep my options open.
But, lordy, it took a monochrome only sensor for Leica to get pretty good at high ISOs. As good as the RX1 sensor ALREADY is at high ISO, it's a little scary how good it might be as a mono-only version. This ought to scare Leica a bit, as Sony in general ought to scare them.
I don't see myself buying it, but I LOVE that they might make one!
-Ray