See forum posts linked for details on most of the new features:
Debianization: http://openenergymonitor.org/emon/node/4067
New feed engine's, nodes interface: http://openenergymonitor.org/emon/node/3868
Emoncms development log March 2014 http://openenergymonitor.org/emon/node/4008
Development: Calculating Wh totals on the emontx http://openenergymonitor.org/emon/node/3995