The state license people who cut hair for a living. In some cases it takes 1500 or more hours of study to be able to sit for the exams. To become a tester one simply has to be assigned the role.
I think a good test is worth at least as much as a good haircut. I don't, however, think that testers should be licensed by the state. I think the industry self enforcement models put forward by organizations like the PMI (for PMP professionals) and ISC (for CISSP security professionals). Of course, what's the difference between a poor haircut and a poor test, in about two weeks the haircut is getting a bit better. The poor test is likely getting even worse in impact.
This is an issue which impacts end organizations, VARs/service providers and vendors. If you want to join in on a related discussion and you will be at HP Discover, on 2:00, Wednesday June 8th an open discussion forum will take place on standards for resources in the performance testing space. Actual room is being secured today based upon interests in attending already expressed.