Good luck trying to take Coursera's Crypto II: I've been signed up since August 2012, and every 3-6 months it has been delayed another 3-6 months. At this point I'm no longer expecting it to be offered.
Crypto I is not vaporware and is excellent.
Crypto I is not vaporware and is excellent.
Crypto I has been offered several times though (at least 4 or 5). If you ever signed up for one of the offerings, you can still access to the full course (videos, lectures, and I think even the automated grader) as well as the forums (but the forum activity usually fades down after the end of the course).