Justin Kiggins has launched the discussion at The Spectroscope.
Those postdocs who are salaried employees, however, are currently "exempt" from overtime pay if they make more than $23,660. The new rules mean that they will need a salary of at least $50,400. So if their institution is following the NIH standard, which sets a minimim of $42,840, it looks like they'll either need to get paid overtime for any work done over 40 hours or get a raise to meet the exemption requirements
Go on over and read, especially for the links to places you can comment on this rule prior to implementation.