The iPad will run your iPhone applications and games out of the box, but you're going to have to do a little stretching to get the full effect.
Since the iPad not only features a larger screen than the iPhone, but a higher resolution screen as well, running existing iPhone apps and games presents a bit of a conundrum. Apple addresses the issue by allowing users to choose one of two ways of running their applications. Small and sharp, or big and slightly less detailed.
"We've built the iPad to run iPhone apps out of the box," explained Apple's Scott Forstall during today's event, showing off a game running at the original resolution, followed by the same game running in full screen mode, blown up via pixel doubling.