Honda is showing off a new GPS with weather info and social networking system (via Engadget). This is a lot like Goole & Volkswagon's proposed nav system.
What is really exciting is the ability to load up personal POI. For example, I am going on a road trip and want to get all my favorite restaurants, WiFi locations, friends' houses, and hiking trails for Michigan and sourthern Canada. This could be a GPX file, or GeoRSS feed from Mapufacture.
The Garmin Nuvi supports this using their POI Loader, which will take a GPX or CSV file and load it onto our GPS. The Nuvi looks really great, but is an external solution. Built-in navigation systems offer better integration into the interior and usually better sensors. For example, my Prius (Akius) has in-wheel hub sensors for integrating distance traveled when GPS isn't available. Now if only the in-car navigation systems (which cost a bundle more, on an order of magnitude) offered similar functionality, upgradeability, and best of all: hackability.