Not to be up-staged by the next generation S-class that will have dual (front and rear seat) iDrive like controllers (predicted by us), BMW is readying this option on certain vehicles.
The MY2005 and beyond 7's and 5's, that are ordered with the rear entertainment package AND comfort access will get a second iDrive controller in between the rear seats.
The rear iDrive monitor also allows the rear passengers access to the GPS system so they too can view the route map and other functions.