There was supposed to be 15, but we moved m5 at the last minute and didn't rename the files to cover the gap. So there's only 14.
R2 campaign follows a smiliar general story to R1 (the EA war) however all the missions are new and follow a new plot.
R2 campaign also will include the second chapter, from after the Gigas arrives.
It should be about 30 missions.