Macrumors has a detailed breakdown of a couple of new iPhone patent applications, but here's the gist: Apple is looking at how to trigger events based on movements (or gestures), and one patent filing shows a front-facing video camera. The camera is easy -- there's your 2-way video chat (we hope). The motion stuff? Well, Apple could go in several directions with that.
According to the indications in the patent filing, Apple is suggesting the interface on the iPhone could change under certain conditions. Specifically, contacts would get larger if you are running. That makes them easier to tap when you aren't able to be as accurate. This is just one example, but I think the more the iPhone can correctly guess the context of its use, the better. We were all a little excited when we saw the auto-orientation of (some) apps, and the relatively minor miracle of a proximity sensor which turns off the screen when you raise the phone to your face. The motion-sensing stuff takes this way beyond all that.
While this stuff won't likely make it into the next iPhone revision, it does show you where Apple is headed: more features, better usability. Although I do notice the power button seems to have moved to the right, away from the top. Will that be part of the next iPhone? There's mention of everything from a stylus to a scroll wheel (like BlackBerry), but I think that's just patent chatter (covering the bases, as it were). Here's a link to the patent filing.
[thanks to Alejandro for help in plumbing the patent filing]