There is a good discussion thread on the QGIS PSC mailing list about the next developments of QGIS. Currently QGIS Wien 2.8 is the Long Term Support release which a lot of folk are happy about as it means we have stability and support for a year and don't have to try keep up with the 4 monthly release cycle. But there are upcoming changes to Qt, Python and other software which will eventually mean a change to QGIS. There are also implications for plugin developers and folk using the API.
It is worth a read to see what the core QGIS folk are doing: http://lists.osgeo.org/pipermail/qgis-psc/2015-April/002986.html
(start here and read on)