There was a neat talk from the silicon valley ethereum meetup a few months ago where a lawyer dives into the technical definition of a legal 'contract' and what parts of that Ethereum code does and does not satisfy:

http://www.youtube.com/watch?v=jSLK3lbENRc

(One of the key insights there is although Ethereum uses the term 'contract' to describe its autonomous code, Ethereum contracts do not by themselves satisfy the criteria for a legal contract in common jurisdictions... 'autonomous agent' would be a better term for Ethereum to use)

All of these links I got from people on a discussion on r/ethereum the other week: http://www.reddit.com/r/ethereum/comments/27gdhc/are_you_all...