Spoilers ahead.
forget you Fi, you made me tear up at your final cutscene. :c
This game is absolutely amazing, I just beat it and there appears to be some "Hero Mode" afterward (must be a hard mode, challenge mode, or Master Quest-style).
I think it's rather obvious that the incarnations of Demise are every Ganon encountered through the series. I wish there was a little more background given on Demise, as well as the establishment of Hyrule, but perhaps the next game. I believe it is quite obvious that this game is definitely the first chronological story too.
A beautiful ending as well, though sort of a cut-off.