• Global shutter… or really fast rolling shutter.
• Built in NDs. Canon, if you remove that mechanical shutter I hope you replace it with internal NDs. No mirrorless body has this and it is way overdue.
They announced a patent a couple years ago for a sensor that would have two separate charge buckets per pixel, that could be switched between instantly across the sensor. The patent outlined that it would provide both these options, plus nearly double dynamic range.
To produce global shutter with this, you simply switch the sensor into bucket B, then read out bucket A.
To produce "built-in ND" you expose bucket A for say 999 microseconds, then bucket B for 1 microsecond, and repeat. That ratio would cut the brightness of bucket B by about 10 stops (2^10~=999/1). The speed cutting between the two would need to be fast enough that the resulting series of still images still would produce continuous motion blur. The speed I mention would be 1ms per exposure, so would be able to make motion blur totally continuous on a 10k pixel wide image (66MP) if an object took 10 seconds to cross the photo (10,000 ms would mean it moves one pixel per ms at that speed). Of course in practice even perfectly focused objects will not be just one pixel wide, and most motion blur doesn't cross the entire photo, so would probably create beautiful blurs at say 1/60th second of a tennis player in daylight, and so on.
To produce HDR, you do the same as "built-in ND" but then use bucket A for the shadows, and bucket B for the highlights. This could produce probably over 20 stops dynamic range. You'd be able to properly expose a daytime interior while the scene outside the windows is also properly exposed. Or, you could shoot a nighttime interior and still be able to read the makers' marks on the lightbulbs.