A year or so ago, a colleague of mine who was working his way up the ladder of the QA function wanted to know if he'd be able to continue into management without a degree. At the time, I hemmed and hawed and said, "It depends, but you should probably get one sooner or later."
In retrospect, I got it wrong. He needs a degree, and preferably a Bachelors in Computer Science.
Here's why. When you apply for a job, you need every edge, every sparkle to stand out from your competition. That's what is required to land a role in our new career reality in 2011.
Because QA is a function which is an entry point for many into a company, or into a software career, there are a lot of people, a lot of competition. To rise above, you need to perform and make the team better (And yes, you're right, a degree is not a guarantor of this result - that's your own hard work). But, to get the interview two or steps later in your carerr you need both those great results, and the deeper Comp Sci background that is hinted at by such a degree.
Hiring Managers hire the best they can find - they want to succeed just as much as you. And given the unemployment rate, they are usually hiring a candidate who is more than the job requirements, not at par.