Phantom Hourglass and Spirit Tracks weren't good, but Ninja Gaiden: DS (damn, that "let's make it so the titles all can be abbreviated as 'DS'" thing was annoying) pulled off touchscreen based sword combat pretty well. I mean, the game could be frustrating as hell if your touchscreen was a little off, but all in all, I did beat it once or twice while enjoying the way movement and combat were put together.
Honestly, though, I just want them to use the Wii U pad as a controller, especially for Zelda. Sure, use the touchscreen for pause menus, inventory, etc., but keep core game play for Wii U titles using the actual controls. As it stands now, I can barely see the point of the Wii U controller, since Nintendo has still shown a preference for their Wii controllers, even when showing off Wii U titles. It just feels like a very expensive controller that will only be used when a developer decides to use a touchscreen gimmick. Though, it might be for the better, having heard that the Wii U controller life is pretty dismal.