I've signed up. Craving a more formal intro to crypto-currencies. Consists mostly of video lectures and supplemental multiple choice style quizzes. Original course included five programming assignments asking students to build simplified versions of a Bitcoin like system, but its not clear there is any programming involved in the Coursera version.
A draft version of the Bitcoin textbook the instructors are currently working on is available:
https://piazza.com/princeton/spring2015/btctech/resources