This post is purely theorizing on the idea of having Dark Link in Skyward Sword.
I was thinking about possibilities for what could happen in the next Legend of Zelda title, Skyward Sword. Dark Link has not been actively present since Four Swords, the last game where he played as a main enemy in a game. Alright, he wasn't the main enemy, but he certainly was one of the higher tier bosses Link encounters throughout. But ever since then, he hasn't played any big roles other than appearing in a cutscene in Twilight Princess and appearing in a mini-dungeon in Spirit Tracks.
But if there is any game perfect for his return, it would be Skyward Sword. Dark Link proved a huge challenge in Adventure of Link (his first appearance), where Link had to put all of his skills with the sword to the test. Dark Link also accomplished to do that as well in Ocarina of Time.
Clearly, Dark Link's biggest mechanic is his sword fighting. Skyward Sword has been confirmed to be one of the earliest games on the Zelda timeline, before the events of Ocarina of Time. Ocarina chronologically introduced Ganondorf in this game, so he clearly could not be the main enemy in Skyward Sword. To me, that leaves an open door for Dark Link to shine again.
With MotionPlus in hand, a fight against your own copy would be the ultimate challenge a Zelda fan would want to face. It would take all the skills the player learns throughout the game and throws it right back at the player.
I can't think of a better enemy, especially with this premise.
But if this isn't the case, I would at least want to face him at some point in the game.
What do you guys think?