Much as I love my DP2 Merril, I just don't see the Foveon sensor competing in high iso situations. Doesn't some of the problem arise from the fact that the lower layers need more amplification because of receiving less light? I'm no engineer, but that explanation makes sense to me, which leads me to think the issue will be solved by an electronics company rather than an optical company. Between 100 and 400 iso, though, my E-M5 just can't compete in terms of resolution. On the other hand it can do anything I ask of it rather well, which is not true of the Sigma.
A niche camera? Decidedly, but what a wonderful niche! I just doubt that the Foveon technology can be made to compete head to head on all fronts with good, general use Bayer sensor units. And I'm not convinced that the problem is Sigma, but maybe, rather, the sensor structure. I'd loved to be proved wrong, however.
Meanwhile, though it may be a minority opinion, I love the simple, straight-forward controls of the DP Sigmas. I haven't met a camera whose interface pleased me more.
On one hand, a Foveon m43 camera would be very interesting. M43 has a mature lens line-up and the ability to easily use almost any lens, given the right adapter. The lenses may not be employed in their originally intended focal length, but it would open a lot of lenses that have never been used with a Foveon sensor.
On the other, the original Foveon sensor DSLR's and DP series used a 1.7x crop, which is closer in size to Canon aps-c than m43. At that size, the sensor had an effective 4.7mp resolution; even with a higher photosite density, would a m43 sensor have reasonable resolution? And would the buying public go for that in 2014+?
Sigma's resources are limited, and they have now consolidated all their cameras to use the same sensor. I'm not privy to Sigma's finances, but one could deduce from their 'spartan' features and overall performance that they don't have a lot of funds to pump into development. Would a second sensor line even work for them, financially? Especially one that would have lesser performance in resolution, low light, high ISO, and video, compared with everyone else?
An m43 Foveon camera - a nice idea, but fraught with difficulties.
Well, considering Leica have squandered a number of good relationships they would damn lucky and should be grateful to actually be accepted into the MFT community. They produce 2 excellent lenses for MFT with their name on them (I've not had a chance to see the new 4/1.2 or recently announced 15/2.8). They need to wake up and smell the coffee because there may not be a demand for Leica rangefinders in 10 years time.