The Samsung NX20 will be an advanced upgrade of NX10/11 model that will have a new design and improved performance. The new NX model will have an EVF. The camera will be announced at CES 2012 which will take place in Las Vegas from January 10-13, 2012. The 16-80mm zoom lens will also be presented and will probably be the NX20 kit lens.
In 2012 Samsung will announce several new NX lenses, at least one of them will be a pancake. Samsung is also working on two more APS-C sensor, one of them is suppose to be customized for video (probably new or improved processor with the same 20MP sensor).
The most interesting rumor I received is that Samsung may announce a second NX camera at CES 2012 but I have no further details at that point.