Publisher Electronic Arts and developer DICE are bringing the Battlefield celebration to the people.
It’s the Battlefield franchise’s 10th anniversary, and fans can hop onto EA’s digital-download service, Origin, and download Battlefield 1942 for free right now. Battlefield is DICE’s long running first-person military shooter series. The most recent entry, Battlefield 3, is available on PC, Xbox 360, and PlayStation 3.
http://venturebeat.com/2012/11/05/ea-celebrates-battlefield-1942s-anniversary-by-giving-it-away-for-free/
It is a short article and there really is not much more to know

If you are signed up for Origin, I'd say go get it.
Edit - Weird... The title got messed up somehow. oh well, fixed.