I will care about 4k when I have a 4K tv. I just know Nintendo oddly cares a lot about lighting so I figure they will have some RT in it. Then use that RT in puzzle solving for a Zelda game or a freaky level in Mario. They will come up with really creative ways to use it in a gameplay mechanic. I care more about framerate than resolution. If a bulk of 3rd party games can at least be 1080P and 60FPS. I'm good.
Bite my shiny metal Cockpit!