It's not 100% corn, in fact, it's mostly plastic. But it is cool that they are starting to use materials that pollute less.
The TV show Eureka used a case made mostly out of potatoes when it released on DVD in 2007.
My only concern with the use of biodegradable materials is whether or not my DVD case or PC will still be around in 10 or 20 years. I mean, it's degradable.