Im pretty sure that you can already get it... only because Ive seen a new C class with the DVD working while moving with my own eyes:
My Dealer sent me to these guys
Mid City Engineering because my ML500 had everything but a backup camera and nobody else even said it could be installed. So I go there and its like a total electronics lab in this little building: they had every kind of mercedes model and they were designing and building all these amazing devices.
So while im getting the camera done I ask the guy if they can do a backup camera for the new C class because i have one ordered for my wife. He smiles and says "come with me" and brings me over to a brand new C350 with the multimedia package. The radio had a little black box hooked up to it that sat just behind it and when they guy pushed a button on the steering wheel the instrument cluster said "video on" and the dvd played while he drove the car around. I guess they design and build these devices in house and they were really knowledgeable. Needless to say i have one of the modules waiting for me when my car gets delivered next month.
Anyway this was like a month ago and he told me that car was the first but they were developing a kit as well. The price the guy gave me was like $499 plus 1 hour of installation so the $1000 price seems a bit high.