Well, the M9000 caliper also reportedly uses a new/different material for the piston. This all really makes me wonder about the M987, which was introduced only a year or so ago. For the next few months, however, the M9000s appear to be vaporware. I am building a bike now and am somewhat concerned about using what may turn out to be a non-standard brake that was phased out after only a year (the M987).
I also don't understand why the new "Freeza" rotors are available in centerlock only. Are they not trying to sell their parts?