It was back in 2008 when Samsung Manager Kyong-Kook Shin suggested that "the firm is actively pursuing development of a full-frame CMOS sensor intended for use in a professional camera" (Source AP). But at that time they thought they would launch it as a DSLR model.
According to a new anonymous source Samsung secretly worked on the development of a new Full Frame mirrorless camera that will be launched in March! If that is true they will beat on time both Sony and Fuji that are rumored to launched their FF mirrorless systems in late 2013 - early 2014. The new camera will be named Samsung NX-R. The name once popped up inside the Samsung support database (now removed).
No specs have been unveiled yet but I hope some other sources may hear the call and can send me an anonymous message at firstname.lastname@example.org to share some more bits. Thanks!