I've been taking the other algorithms class (Sedgewick and Wayne from Princeton), which has been interesting and informative so far.
I'll second your statement about the usefulness of these classes for people who are self-taught - I'd been trying to go back to school to get a CS degree, but working full-time and not being very close to any universities made it difficult. While I won't get an actual degree from these online courses, they have been really useful so far for filling in some gaps in my knowledge.
My algorithms professor is using the videos from the Sedgewick and Wayne course entirely as a way to present new material in place of lectures. He's teaching their book and his view is essentially that his time in lectures is better spent answering questions and interacting with the class than introducing new material that has been extemely well presented on the web already.
I can attest to the quality of Sedgewick and Wayne's lectures, and I have a lot of respect for my professor's humble and novel approach to teaching this course.
I'll second your statement about the usefulness of these classes for people who are self-taught - I'd been trying to go back to school to get a CS degree, but working full-time and not being very close to any universities made it difficult. While I won't get an actual degree from these online courses, they have been really useful so far for filling in some gaps in my knowledge.