[Brightcolours]

I'm old school. Used to take landscape at F8 and get good depth of field and sharpness.

Soon we'll have to choose big depth of field <b>or</b> sharpness.

No, you don't. It is not the sensors doing anything, except showing more and more what the optics do. So, if you now get sharp big prints, you will get sharp big prints in future too. The only thing higher resolution sensors do is allow you to zoom in even more on the  image projected by the lens. Not something normal to do in normal photography, looking at images with a magnifying glass... It is about the image.