Some states, as i understand it, allow you to practice law by just sitting for their bar test and passing.
No aba law school needed. that would be the closest thing i can think of to what you're talking about. I do agree that credentialing in the us has gone off the deep end. But that isn't to say there should be no regulations, just that the barriers to enter a field should be rethought. its stickier than just giving a test and offering a degree though; sunni's comment is somewhat appropriate in this regard, but it isn't as if test anxiety wouldn't effect a regular course of study, since you would presumably be taking tests throughout your education. But, LD exceptions made in those scenarios could conceivably be made in the scenario pada put together too--like unlimited time for people with ADHD or test anxiety for example.
i don't really see a tremendous problem with this kind of arrangement in theory, but i doubt it would be equitable in practice, particularly since very few people have the resources necessary to educate themselves enough in specific subject matter to pass a test like the one pada proposes. you end up just shifting where the money gets spent--instead of on tuition, its straight textbooks and you've got to have the time to study and take the test. Test writing is also expensive.
to the person who suggested the act/sat thing...those tests test your ability to reason (and were once thought to test your aptitude for learning) or think critically, and conduct basic mathematics. That does not suggest much about your proficiency in any given subject matter. Unless you suggest there exist a general "bachelor of liberal arts" or some such nonsense the way some grad schools try to extort money for a MALS (masters of arts in liberal studies).
to the notion that educations are worthless if they aren't marketable, i disagree on principle with that. the problem is not that a degree in x humanity is worthless, but rather that someone pursues it thinking that it is marketable. If you go to college with the hopes of simply getting a better job, stick to courses of study that are heavy on internship/externship stuff, and are directly applicable to a specific occupation. Or better yet, go to a trade school and learn a skill from a master. Knowldege production should really be the only goal of the university/academy, but only people who are truly willing to live a life of the mind have any business being involved in that industry--the knowledge production industry.
just my two or three cents...
be easy,