Just a heads up that a new course just started on Coursera.
The Science of the Solar System
https://www.coursera.org/course/solarsystem
Probably not as good as the Introduction to Astronomy by Duke University, (it's not running now but you can sign up for the watchlist or just look at the class archive.) but I thought some of you might want to check it out. Maybe we can form a study group if there's enough interest.