Is everyone else familiar with this? Because this article
http://artsbeat.blogs.nytimes.com/2013/01/18/popcast-new-owners-for-vintage-hits/
is the first I'd heard of it.

It seems a US law passed in 1978 meant that the copyright to music (actually not sure if it covered other works) reverted to the author after 35 years, meaning stuff released in 1978 will now revert to the songwrighters, presuming they put in the necessary legal legwork.

Not sure how much of a difference this will make, though. Listening to the podcast they all seem fairly sure the artists will just licence their stuff back to their own labels for a healthy fee, which is probably what I'd do.