Are class schedules really necessary?

(via Dangerously Irrelevant) Shawn Cornally at www.good.is has written a great post about totally restructuring the way that schools organize education -- getting rid of the schedule blocks, and just giving the kids goals and teachers.  It sounds like an awesome idea to me.  (I think I would have done a lot better in the chemistry labs he describes.)

What if we removed the passive course-to-course drudgery of the school day? What if there was no schedule? What if students were left with a list of coyly worded benchmarks targeted at creating quality humans, and we just waited to see what they could do? What if teachers were seen as mentors for projects designed to help students meet those benchmarks? What if the students initiated these projects and the teachers spent their time recording TED-style talks that would serve as inspiration and help students generate benchmark-related ideas?