I've played with your alpha site a little and i think it would have useful applications here at Sloan, especially since you can customize the types because we have problem sets and cases, mostly. This would be especially useful for the problem sets and their solutions.
I do have a concern that the evaluations and assignments portlets take up a lot of real estate, but i think that can be resolved by setting them up on their own page within each class.
When i selected "view my answer" for test1 - after uploading a file, etc. - i got an error, though: "We had a problem processing your entry:
You must supply a value for revision_id
Please back up using your browser, correct it, and resubmit your entry.