This sounds familiar - some of the old PowerMacs had this crazy 45 pin connector that "...incorporated capabilities for video out, video in, audio out, audio in, and the Apple Desktop Bus (ADB)" (http://kan.org/6100/graphicshardware.html#hdi45). The new Displayport sounds like a modern take on an old, er, classic?
Wow - guess Apple didn't do any market research on this one! Just needling you - apparently enough people don't velcro them to the dash, though that this seemed like a good idea - guess we'll see how it pans out.