See the video embedded in here:
Jaguar XJ with BlackBerry integration hands-on (video) -- Engadget

Basically the screen from your [BlackBerry] touchscreen phone is displayed on the cars infotainment screen via USB (RealVNC), where you can interact using the phone's interface. The phone get's charged while you have access to some of the phone's apps (some are blocked for safety). Other phone types may be supported later on.

If I'm honest I don't see how useful it would be exactly, besides being a cool and novel concept. My car can perform those functions he demonstrated via RNS-510, 9Wx bluetooth, MDI, and steering wheel controls (better) as well as the touchscreen.

Anyway, thought you might be interested nonetheless.