VW/Audi and other German automakers have had electronic parking brakes for several years now. I am not too keen on them, because I like to be able to modulate the parking brake force w/ a good old-fashioned pull-up lever alongside the driver's seat. Also, you need VAG-COM software and a USB-OBD cable just to replace the rear brake pads and/or rotors, because you have to tell the brake computer to back off the pads.

I worked at TRW when they were developing electric power steering, which has since become somewhat commonplace. The major debate centered on whether to retain a rigid mechanical connection as a backup. (It was retained.)