It would be nice to do a fan edit of The Muppet Movie. There's a really obscure cut out there which is longer - I only have it in Pan & Scan and in terrible quality, wish I had it better, as it has a longer version of "I hope that something better comes along", and most notably a better ending - the Muppets talk over the credits! Really amusing, nice stuff there. I think that the ending is actually the same edit visually, only the sound is different (with the Muppets being audible as they talk) ... So it would be possible to make that change easily, just that one change to the ending. Hm.
In the Classic Jedi thread, I discuss the best way to do an extended fan edit of Army of Darkness. I did one years ago. You have to use the Hong Kong DVD, as it's the best quality out there, and "hack" it, a la the Classic Editions. For most of the movie you bypass your editing software and put the raw M2V files directly into your DVD program (DVD Studio Pro), then only edit the extra deleted scenes (the four from the Television cut and Anchor Bay discs). Extend the opening with a bit from Evil Dead 2, and include both endings via seamless branching.