Originally Posted by DebauchedSloth
They don't get the audio from the three pins. They detect that they are docked from the three pins, they then auto-pair and send the audio over bluetooth to the dock in question - hence the audio port (and the high price of the dock, BTW.)
This is exactly how the Nexus One worked. It has the same three pins. Probably the dock would work with a GN, if you could manage to get the GN into a N1 dock. Hmmm...
You can see the dock detection code in the kernel source, BTW.
I haven't looked at code in years! Are they expecting a High or Low on the detect pin?