Not looking for megapixels -- 21 is already too many for FF. Huge files, slow transfers, slow processing.
Looking for better low light performance; lower noise; better EVF previewing for longer exposures; GPS; wireless downloading; wireless charging; programmable exposures longer than 30 seconds; Switchable IR filtering (or none... I'd be happy to slap an IR block filter on the lenses when shooting normally.) (C'mon Canon, don't you want to sell a boatload of highly profitable filters???)
You know... things that will actually improve the images and the regimes, and the shooting experience, as opposed to giving us, yet again, an even more detailed view of the flaws in the lenses.
But of course, what we'll GET is... more megapixels. Bigger files. Slower processing. Slower transfers. Oh yeah, and more effort wasted on trying to inappropriately multipurpose these beautiful still cameras into video cameras. And maybe a new battery style so as to obsolete the hugely expensive ones we've already bought.
I am *so* tired of "Hey, look more megapixels!" and frankly, I'm not going to buy unless the camera actually performs better. Increases in megapixels work *against* my buy-in. And no, throwing out half or 3/4ths of the pixels in the camera isn't the right way to go -- the less sensor area involved in taking the shot, the more noise there will be. With a nominally high megapixel camera, you have to take the entire image and then bin the results in order to approach the actual noise reducing effect of larger sensels. So modes like SRAW and SRAW2 don't really help (unless the cameras are modified to do the binning, that would be a useful change.)