What can this do? More like what can't this do! The CK-20W puts "communication, music, navigation and push-to-talk" into your hands—the same hands that should be on the steering wheel instead of diddling with this.
No matter. A compatible phone with bluetooth A2DP can stream music to the device instead of playing on the phone's tinny tiny speakers. iPods or other MP3 players can also be plugged in through the included cable.
If you've got the Nokia Navigation Pack LD-2 and the included "Route 66 Mobile 7" software that works on Nokia S60-based phones, you can hook those two up to the car kit also.
Lastly, push-to-talk allows you to hit the button on the CK-20W instead of on your phone to activate your PTT functionality.
Both the car kit and the navigation pack should be out by Q3 2006.
Nokia Multimedia Car Kit CK-20W takes multimedia from mobile to automobile [Nokia Press Release via Mobile Mag]