for what it's worth, if you take the ML class, you will learn most of the things you would learn in the AI class and more - although it does get a bit rigorous, and will take more time than the AI class would.
this is easily one of the best classes i've been able to take - as i said in the other thread, i was surprised to enjoy a 3-hour midterm! i think it's awesome they're making this available to more people.