You know I actually hope they don't include anything with this pre-order. My reasons for wanting that are pretty selfish though.

In my area there is no practical need to pre-order anything. I walked in and bought a GBA on a whim at launch without any pre-order and I even got to choose the colour. There are virtually no rare Cube games. Ikaruga, Cubivore, Skies of Arcadia Legends, even the Zelda Collector's disc have been readily available in stores in my area since they came out. I live in an area with a good sized population that for some reason is not that interested in games.
I like to buy my games from a local chain. They have a great selection of both new and used titles and they always have the lowest prices. Plus the staff is really cool and never pushes ANYTHING on the customers. However they don't take pre-orders because they want people to be able to walk in and buy a game at release instead of missing out because everything was pre-ordered. I like that idea but it screws me when it comes to pre-order incentives so in situations like Wind Waker I have to go to EB who a. charges nearly ten dollars more for new games, b. only knocks three bucks off of used titles, and c. pushes strategy guides and GMR subsriptions on me. In other words I hate giving them my business but when Nintendo offers something major as a pre-order incentive I have no choice since the only other places that pre-order in my area are Wal-Mart and Toys 'R' Us and I sure as hell don't trust THEM to give me the free bonus disc I'm entitled to.
Personally I don't think this new Zelda even needs a pre-order bonus. Wind Waker was getting a lot of criticism for it's looks, even from longtime Zelda fans, so including the unreleased Master Quest was a great way to build interest. Here they don't NEED anything extra to build interest. All they have to do is release a video preview on a DVD, give it out for free at stores and have stores run it on a screen in a loop, and nearly everyone who sees it will buy the game.
Edit: Here's another idea. They could pull a ZOE and include the Zelda demo with another game. Sneaky but since most Nintendo games are worth buying anyway I don't have a problem with it. It could boost sales of another game (like Fire Emblem?) and would be a good way to test how interested people are in it.