It seems plausible to me - they're talking about the buttons on the wire going up to the buds communicating back to the device... I'm certainly no expert, but I can't think of any other devices that do that via a standard 3.5mm socket.
I doubt they have a patent on the headphone thing. My Nokia N-series phone has a 3.5" headphone jack and it ships with an inline remote that is similar in functionality to the controls on an iPod shuffle. My Sony and Panasonic portable CD players from 10 years ago also had a similar thing.
I have an old MP3 player that has a volume control, play/pause and skip in the earbud wires that go to a 3.5mm jack (but the earbuds have a 4-conductor plug). Also, the 4-conductor 3.5mm doubles as the USB port for uploading songs to it. You can also use normal 3.5mm headphones with it, you just loose the volume control functions.
