I quite liked the sailing from WW and wouldn't mind it in a future Zelda. The only problem with it in WW is that it relied on the sailing too heavily, with very few large islands to explore.
Most of what I feel has already been mentioned, so I'll think of a couple other things.
1) A tiny Hyrule. True, Hyrule gets a little bigger each game, but I still think its woefully smaller then it should be. Zelda, at heart, is an exploration game. So give me lots of places to explore. I...