I wonder how much longer these services are going to stay free. I like to download all the content just to be sure that it's not taken away when they eventually go to paid models.
I also download everything. I'd hate to want to reference a lecture later only to find it missing.
Last I heard, Coursera was still searching to find a revenue model. I've noticed their "resume" section expand, and you can now opt in (or is it out, by default?) to job hunter searches. Which makes me curious as to what Coursera's revenue-generating product is going to be. Is it the database of people with certified(-ish) skills, or will it be the content they provide?
I've been thinking that a viable model that would keep courses free might be to use a kickstarter crowdfunding model to launch a course offering. If I did it, I'd set it up so that the threshold was high enough to make sure that the course was profitable, then make the course available to contributors first (and they'd get certificates), after which it would be freely available to anybody who wants to take it. You'd have to work out how to do the advertising efficiently so that it didn't eat your time and profits, which is probably a huge problem with the idea. Personally, I'd happily contribute to something like that on a regular basis though.
Periodic relaunches could also be set up for certificate track stuff. You'd get the professor back in to answer questions and all that, but the video content could be left the same so it should be much less expensive to operate existing courses.
I bet the end goal (for all these MOOCS) is to become the de facto source for web based courses offered, for pay, through the current university system. You're right, they're also trying to become a recruitment tool for various industries, but they'll make the most money by switching on the revenue steam once universities become dependent on them and there's no turning back.