interesting concept, but what would it lead to? Like it or not most students go to college because they want to make money. How would a degree in martial arts help you get a job? A 4 year degree won't qualify you to open your own dojo, and won't even give you a leg up in whatever system you decide to join with the eventual goal of being an instructor. Then there's the small bit that karate teachers don't generally get exactly rich unless they run a bunch of large McDojos.
The only thing I can see it qualifying you for really is teaching at a university that grants the martial arts degree, which gets rather circular