I'm betting the real killer app will be a game that centers around environments with lots of liquid-solid transitions. Maybe you'd manipulate and move various liquid and gel materials around in zero-gravity, or something. Maybe an "infinidistillery" sequel to Infinifactory.

Or, come to think of it, a "Half-Life 3: Portal 3" where you use gravity+portal+various paint (and other liquid) guns, on an alien ship and in space, would make a lot of sense...