It could happen!
Cut, copy, paste, move, regenerate, etc. are all available and working today. We don't have any multi-world plugins installed, but it shouldn't be hard to either update the one I wrote ages ago or use one of the many existing plugins.
I like how Bryson pitched this idea in-game: each of us gets one structure, but everyone else gets to choose which one that is. For example, 709 doesn't get to choose which of his projects to bring over. Instead, the rest of us effectively vote to decide that, say, the UFO is the one structure we import to this world. Clever!