Clue Tokens or similar that are chipped and show an image, map, play a sound file or similar could work really neatly in an adventure or mystery style game.
I think the best way the surface can be used in boardgames are in those games where a modular game board is used or a game where a modular board would benefit. You mentioned Small World as one option but I think it could really benefit one of my other favorite games, which is Ghost Stories. Imagine creating a map on the surface using flashy graphics of ghosts, detailed tile images, portals and even villagers. It would also be great for those games like Formula D, Dungeon Twister and such which have a huge expansion base. Buy a code or a download for maps for Formula D that can be used with the game or Dungeon Twister creating easily turnable dungeon squares adding even shifting squares.
There was talk (about a year ago) on The Gadget Show (CH5 in the UK), of an electronic gaming table being developed. This got me really psyched cos if you could buy electronic modules of great boardgames, apart from looking cool, you could remove all the tedious setup and teardown times, and coolest of all, save games in play. For wargame fans like me that would be superb. Not got time to play a 10 hour game in one session? No problem !!
Also, could the directionality of viewing the screen be used in it's FAVOUR? Touch your cards and they all become visible, but only from your direction of view. touch them again and they go face down again.