My take is that 24MP makes no sense at all.
I agree. The idea of Sony developing a new lower resolution 36x24mm sensor along-side its involvement (almost certainly) with the 36MP sensor for Nikon sounds like a forum fantasy, from people who are unaware of or in denial about Sony's sensor division relying on the economies of scale achieved by selling sensors to Nikon as well as to the Sony camera division, coming from the fact that Nikon can sell far more of a sensor in its DSLRs than Sony can of the same sensor in its own cameras.
Or stuck on the fallacy that a lower pixel count in the same size can significantly lower the cost of the sensor. Or deluded by the fashionable "anti-megapixel myth", that a 24MP sensor would give better IQ than the 36MP one for the D800 when one compares images displayed at equal size rather than individual pixels or 100% crops beloved of some "squints".
Or the other myth that a company struggling at third place in a product sector will deliberately hobble a product to protect sales of its own more expensive products, when in fact the main effect will be to steer sales to competitor's non-hobbled alternatives. (That is, hobbling is for companies in a monopoly position, or who have customers locked in by backward compatability needs.)
One side issue I am interested in: if Sony does offer a full 35mm format camera with an EVF, how large will the EVF image be? I see no major reason for it to be different with DSLRs of different format sizes, but as far as I know, Sony's current SLTs have a smaller VF image size than the A900 or any other 35mm format DSLR. I am apparently in the minority in prefering
a VF image smaller than in any 35mm format SLR, for ease of framing when using AF, and with an EVF allowing manual focusing tools like peaking and zoom, the last reason for the larger VF image is gone, for me. And the failure to offer that large an EVF image in any SLT camera so far, including the A77, hints that Sony thinks the same way, but I can see the marketing problem from those who revile "tunnel vision VFs”.