According to Brett Friedman (writer of the clone wars), he said that the scripts for season 7 and 8 are finished but not animated yet. If we convince the Disney Chairman to bring back the remaining seasons of the Clone Wars, then Clone Wars will be back!

Star Wars: The Clone Wars season 7 & 8 have been written out according to Brett Friedman, but we need to convince disney to bring back the seasons onto TV!

Source: http://makingstarwars.net/2014/05/brent-friedman-writer-clone-wars-talks-season-7-8/