A few years ago I worked at a company that created high-end HMI (human-machine interface) design tools -- the kind used for things like airplane cockpit control panels. One of the interesting things I discovered was that the same toolset I was initially working with was also used to develop interfaces for certain European cars, allowing the driver to access a myriad of functions (GPS, MP3/CD playback, radio, air conditioning, etc.) through one panel that changed displays based on function.
It struck me then that we might be approaching some sort of tipping point. People are taught to drive cars the same way as they were forty years ago, despite the fact that many cars are built differently (whether tiny compacts or hulking SUVs) and there are far more controls at hand on the dash -- as well as some that we add on ourselves, like MP3 players, PDAs and mobile phones. If things have become so complex that need ever more sophisticated interfaces to help streamline them, then something, somewhere needs to change.
There's an interesting article over at Engineer Live(you may have to register; it's free) about one possible way to deal with this: change the HMI. In particular, the author discusses different kinds of gestural input technology, which would allow the driver to manipulate control systems without taking his or her eyes off the road. He explores the technologies that already exist, their benefits, their limitations, and some of the systems that have already been developed. If you want a peek into the possible future of driving, where gestures mean something aside from the, ah, suggestions you provide other motorists, it's well worth a read.