The M series is no more. Effectively replaced by the Fuse series which is nylon frames with NASTY. Fuse AT and Fuse SE are replacing the M9 and M9Se, Fuse RS and Fuse GT replace the M11 and "introduce" the M11 with hybrid strap technology.
They're lighter, less frame (better board feel), still the rockered frame, and now canted with a new blown foam footbed. Think like Ride Hyphy sole, Burton EST light soles, or Crocs. Just as light as EVA but with better dampening and shock absorption as well as better durability.