I just wish you could take the classes at your own pace. I'm getting very little out of the "certifications" or whatever. And the TA's/Discussion forums tend towards pretty useless because of how disorganized they are.
As a special gift, it's allow you to archive the courses for later review.
While for users it's free to take the course, the offering company probably has to pay fees to whatever IaaS they're using to run the grader(s). I would imagine to make it 'cost-effective' for their purposes, they'd be interested in as many people as possible benefiting from the grader's functionality if they're being charged by the hour for example or some other block-allocation unit.
I would suggest giving Udacity a try as well. Most of their courses do not have deadlines.
For example, here is a great course they offer on web development: https://www.udacity.com/course/cs253 , co-authored by one of the Hipmunk and Reddit creators.
They do allow you to download the videos, so if you're planning on taking a class from one of those schools at your own pace, just be sure to download the lecture videos and slides before the end date.
[1] https://www.coursera.org/course/optimization [2] medstats.class.stanford.edu
I found that it's very plausible. I still have couple of Udacity classes half finished, thinking I can always come back later, while working furiously on Coursera's deadlines...