Hmmm...so you want us to predict what Canon will do in the next 4-6 years in sensor tech and the various ADC & processing firmware/chips? Ya...good luck with that.
Ok, fine, I'll put what I hope we get in the next 5D/Flagship in 4-6 years. I hope we get better read-outs that will reduce/eliminate the banding we see quite a bit when we have to pump up the exposure, more usable dynamic range, maybe even moving up to 14-16 bit (or have a mode to go to 12-bit readouts for faster FPS?) and better quality at mid-range ISOs. So a somewhat improved 100-400, and improved 1600-3200 (which is the new mid-range ISOs), and hopefully with the better ADCs we'll get improved high & super high ISO performance.