The city Line will have two new stations: Stockholm City and Stockholm Odenplan that make a big difference when changing between commuter train, subway and bus. At the same time the capacity for all trains will be doubled. When the City Line opens in 2017 it will be a part of SL:s commuter line.
Read more about the City Line at Trafikverket: http://www.trafikverket.se/citybanan/
Read more about the City Line and the new stations at Trafikförvaltningen/SL: http://www.sll.se/citybanan/