Obviously, like always, there should be some new enemies added too.
Sure, Wynaut add a few more?
I agree with many of the people here that Nintendo needs to bring back the old classics. We've seen Stalfos. We love them. Keep them. But what about the majestic, fearsome Lynels? What about the Goriyas and their boomerangs? Zelda II introduced a lot of enemies which we never saw again. These guys would look awesome in HD, I know it, and this is exactly the kind of nostalgia the next Zelda game needs.
Obviously, they should create many new enemies to spice things up a bit. I felt like The Wind Waker and Skyward Sword were a bit lacking in enemy presence, since they didn't have an overwhelming variety of them and several of them were simply different forms of earlier enemies. Let's see some brand new enemies that don't necessarily pull from earlier incarnations and a total enemy type count that reaches over sixty. Not critical to success, but it would help oil the cogs a bit.
I also want to see horrors like the Dead Hand and Gomess realized in HD, although truth told, Nintendo should be careful how they use them. If the Dead Hand was so terrifying as an angular blob, what will it do to your average eight-year-old in HD? Maybe it would be better saved for a horror-themed optional dungeon or another T-rated Zelda game, but I still want to see it again. And the Gomess. That thing was horrifyingly majestic, and it deserves another chance.
Iron Knuckles probably deserve a comeback more than Darknuts since we haven't seen them in so long, though I, too, believe they should be in the game together. I don't see a problem with too many armored enemy types so long as Zelda steps up its combat. The details of that are for a thread of their own, but Zelda needs to allow more freedom, aggression, and some sense of realism in its combat if it wants to truly grow there. I bring to mind the final levels of the Cave of Ordeals in Twilight Princess, where you could be squaring off with as many as five Darknuts at the same time. It was difficult, but in a bad way because the combat scheme was too simple to allow for a flowing battle. You just swing your sword almost randomly at a bunch of armored guys hoping to find an opening. Zelda needs to expand its combat before it even thinks about expanding its enemy roster.
To summarize, I want to see a small army of classic enemies in addition to a few memorable bosses or mini-bosses of old and some new foes, but Zelda needs to improve its combat for this to mean anything significant, particularly in the armored enemy department.
Oh, and Like Likes. Give them back, please.