Peter,
Not sure that OPEN versus CLOSED systems is really relevant after this. Essentially, there may be three systems (Phase, Hasselblad, Leica) and each will be more or less "closed" to the others.
While all of this consolidation and stuff sounds great, what happens to the rest of the gear lineup beyond the backs that Phase makes? What is really happening with bodies and lenses? Where are the leaf shutter lenses and T/S lenses from Phase/Mamiya?
Not saying any of this to be disparaging, but fewer players, even if they will claim to preserve the name and direction of the newly acquired others does not mean it will always be a better or healthier situation. It is good to see struggling entities that do produce good parts be kept viable to some degree, but how long can that be sustained?
Honestly, though we may have seen this coming, as Guy states, we still really have no real idea of what this means going forward, and for how long. Phase may become the great aggregator/consolidator operation for MF, but they now have a lot of very different pieces to really get assimilated. If they do not keep up with advances in bodies and lenses, like Hasselblad is doing, or Leica may be offering, so what if they have great backs that cannot be used with equally great bodies and lenses? Not saying they are in that situation now, but that is a possible future they will have to manage, I think.
LJ