Some recent articles about the value of an LLM (from a US perspective).

http://www.law.com/jsp/nlj/PubArticleNLJ.jsp?id=1202472170557&Cash_cow_or_valuable_credential&slreturn=1&hbxlogin=1
http://blogs.wsj.com/law/2010/09/20/the-llm-a-valuable-degree-or-a-wasted-and-expensive-year/
http://abovethelaw.com/2010/09/what-is-the-value-of-an-llm-degree/
http://www.biglaw.org/news/show/3885/will-an-llm-increase-your-employment-prospects