An interesting micro-site – it seems very much more aimed at people who know BLS data already, and much less aimed at coders. The FAQ answers the question "What is an API?", but doesn't even have a list of the IDs required in order to get any data whatsoever out of that API. It does however point to this page which is helpful, if not comprehensive: http://www.bls.gov/help/hlpforma.htm

And the API itself seems quite simple and easy to use - so it looks like good access to important data.