It makes sense, just as much as why a base model car has tin cans for rims, I doubt it's because they dont have more nicer rims to spare. If they didn't divide it up that way then you'd pay full price for the biggest package even if you didn't use 50% of the features.

I thought I heard it was using sky drive to make the cloud happen, could be wrong, just overheard on a .NET podcast.