Hey guys, new to the forums!
Anyways, on the note of a Mt.Doom set... I think if they included an ork camp outside the mountain, along with Frodo & Sam's ork disguises, we could recreate not only the destruction of the one ring, but also a few scenes prior to that where Frodo & Sam are trying to blend in with the orks. So maybe...
Frodo - new print and armor
Sam - new print and armor
Gollum
Ork Pit Master - possibly new mold with Azog/Bombur style potbelly
2x Mordor Orks
With those minifigures along with Mount Doom interior/exterior and the ork camp, I could see this set being loads of fun with many play feature possibilities. I love the idea of getting a Sauron minifigure, but I think he'd be better paired up with Isildur in a smaller "Wizard Battle" type set.