I recall Miyamoto saying that he probably wouldn't use the same system for a Zelda game again, in an interview. He may, but it seems unlikely. I don't care either way, though.
I don't know why everyone wants another full-on story thing again. You can't have those all the time; side quests are fun, too. And you know that the game doesn't feel like a side quest as you play it, just when you look back, after the ending.
I don't know about the Legend Forgotten thing, but what I read said it was the tentative title of the GC one.