According to James Wagner of the Washington Post there have no talks of an extension for months. This jives what reports that the Nationals were willing to trade Fister and/or Jordan Zimmermann.
Both Fister and Zimmermann are free agents at the end of the 2015 season and the Nationals probably know they cannot afford to keep both.
Fister started 25 games in 2014 going 16-6 with a 2.41 ERA and a 1.08 WHIP.
We have yet to hear whether or not the Nationals have had any recent talks with Zimmermann. It was widely reported that at the end of the season the Nationals offered both players contract extensions which were seen as below market value. Even if one of these pitchers is traded there is no guarantee that the other will stay beyond 2015.