I think that the M2 sounds great! Will be a nice evolution of the 1M program, which means that it will remain a driver's car - albeit bringing the advancements that a 2016 car should bring over a 2011 vehicle, particularly the track-based engineering.
I'll echo other sentiments on this forum and say that if I didn't own a 1M I would most likely buy an M2. As I'm unfortunately not in a position to own both and I don't intend to sell the 1-er, I'll be watching from the sidelines until perhaps a CSL/GTS variant is released