A lot can be done here, but as I said some technologies aren't ready for prime time.
In my opinion if you want to introduce new methods of interaction, you've to do it in small steps, the "acceptance problem" is a big issue here.
I think Nokia is doing that in the gestures area, they introduced only a few gestures in selected phones (e.g. flip the phone to reject a call), and these gestures are very intuitive and are accepted around the world. This way they improved the user interaction a bit, without breaking none of the interaction methods already familiar to the users, reducing the acceptance of the new form of interaction, but more can be done IMO.

A innovative system in this area would be a system capable of translate natural actions to the way we use our mobile devices. Of course gestures can mean different things to different people, in order to deal it that, the gestures system should be adaptable to each user. Using the device sensors combined with learning algorithms, we can achieve it now, for the basics/most used rapid access functionalities of our mobile devices.
Such system could reduce a lot the user intervention needed to operate an mobile device, and would be much more easier to operate the device "on the move".

This is just a example, much more can be done in order to achieve a natural and intuitive interaction with our mobile devices.