Yes, any developer worth the title should have unit testing in his skillset. In fact, it should be such an assumed skill by now that it should not have to be on the resume. It's only recently becoming a must-have, though, for the purpose of getting a job -- because we're probably lucky if even half the professional developers out there have ever done it, and hiring managers are even less informed about the importance of unit testing (and, in particular, test-driven development).