The guys at Illusion Labs are no stranger to getting their games running on crazy hardware setups. If you've played Touchgrind [$4.99], watching this video of the game running on a giant multi-touch surface will really make you want a similar multi-touch coffee table in your living room.
The latest thing out of the Illusion Labs labs, is a 24" Apple Cinema Display with an accelerometer on it-- Presumably either an iPod touch or an iPhone duct taped to the back. They then put together a custom build of Labyrinth 2 [$4.99 / Free], only instead of just rendering the same game at a higher resolution, they kept all the components the same resolution and made the levels much bigger.
Obviously the 24" display is higher resolution than the iPad, but the following video gives you a great idea of what some of the iPad optimized games could be like:
Also, we recently stumbled across a video of a massive multi-touch game of Missile Command, although a lot of the skill required to play the game seems to be lost when you can launch ten precisely targetted missiles at once just by touching with your hands. Either way, these giant tech demos of iPhone games are really getting us excited for the iPad.