Okie, so this is what I've spotted so far. And Yes, Video is my priority.
First up, the biggy. YES!!! The ISO no longer changes when a K-M lens or a K-A lens in Manual Iris positions is used.
This means that anyone wanting to use M42 mount lenses, or non K lenses with adapters, will be able to do so with confidence that the ISO (or Gain in video terms) will not change.
For comparison, I put the ISO in Auto, and it then alters, but it no longer does with a fixed ISO setting.
For me personally, this lets me be a lot more creative when shooting in varied lighting.
Unfortunately, no kick up in the data rate - it's still reported as around 20mBit/sec in QTPlayer's Movie Inspector.
And the Audio is still 32kHz sample rate.
Will edit post as I see what else is different, feel free to add Photo-Centric comments for those whose focus is stills (Pun intended)