I'm hoping the bodies of water have fish we can see (if the water is clear enough) and catch. So you cast your fishing rod with your lure and bait, and might even see a fish swim close enough to the bait and chomp down on it. This pulls on your fishing rod so you know to start reeling it in. Could even have bit of a tension system where you need to watch the rod, if it bends too much the line might break so you have to stop reeling it in before it does break. No not a minigame.. just a fishing gameplay mechanic.
To cast, maybe just hold right click and release. The longer you hold, the farther it is cast (within limits of course). Maybe once the lure is in the water, you can use + and - to reel the fishing line out or in. Some simply enough stuff to make something like fishing fun.
Plus if there are fish in the water we can see, it opens it up to have a spear fishing thing like in Stranded Deep.
@Meltron I think we will see the most basic form of farming. Just so peeps don't get confused or expect too much etc..
Water is hard the folks at Everquest Next just discussed that at length in a youtube talk on their site. Markus (Notch) Persson squared the circle on that one but even at his low resolution voxels a lot of flowing water is a lag machine. If Red or any of us crack it we can expect it to be a serious innovation everyone will want to play with.
PS Markus is now officially a billionaire, ka ching.