Yeah you're right, but there are differences. MIT just post their course material online, and sometimes it is outdated (courses given 2 years ago or more). I had no idea about UC Berkeley, they seem a lot better, they have a whole website dedicated to online courses and they even give real credits for them.
The whole idea that Coursera helped popularize is that of the MOOC - a fancy term for an interactive online course. For example, in the economics course you can participate in a market simulation with other students to test out economic principles, in the game theory course you get to play some games and then chat about the results and Nash equilibria with other students, in the literature class you write essays and get grades in real-time etc. (Google for Daphne Koller, TED Talk for more info).
So it's not just course materials, it's a new approach altogether. Moreover, they give out certificates of accomplishment at the end of the course - signed for example, by a professor at Stanford - depending on your performance at the tests (however on the certificate it's also written that they cannot verify your identity).
Anyways, enough with the details. For the surprise ending, I just found out that MIT & Harvard have also started they online course platform called edX (it's identical in concept with Coursera), so now we have basically the best Ivy League universities offering free, online interactive courses. The website is:www.edx.org