“Oh, look kids, there’s an old abandoned Skyrim up there on the hill! Let’s put on a show!”
It might sound ambitious, but they’ve already completed all the Lord of the Rings landscapes as a huge quest-free landscape mod for Skyrim‘s predecessor Oblivion. If you’re making Lord of the Rings machinima, and need the landscape video-backdrops, that sound like the mod to have. Controllable weather, lighting, wind-blown trees, moving skies, and more… but you might want to wait until they’ve ported it to Skyrim, which it seems they’re planning now we have the Creation Kit.