Darknuts, Iron Knuckles, and Moblins; I hope are all in Skyward Sword for their difficulty. They will all surely be more of a challenge with the new motion control scheme, like something akin to God-tier in a fighting game! I also chose the Wolfos, because I'm a wolf fanatic, though I know that isn't a good reason. He heh.
Last, but not least, I chose the "Other" option. I want to see more enemies from 2D Zelda games, such as the Pols Voice, Goriya, Hinox, Ball and Chain Troopers, and Lynels. (There were technically Pols Voice in Phantom Hourglass, but they don't count for various reasons) I guess it would kinda be cool to see them in Skyward Sword's graphics, let alone 3D.
I want them to do something clever with the Cucco's like they did in Twilight Princess, I found that amusing. I'm going to be different, and say I want Peahats to appear. I loved those helicopter pineapples, and that rush you got from running away from them as fast as you could. Not to mention they are quite amusing. Also, IronKnuckles could prove to be quite formidable with the use of the Wii Motion Plus, and I think ChuChu's are a staple Zelda item, can't go wrong.