All of this would be trivial for Apple (or someone creating a plugin) to implement. Apple's flagship photography software aperture already allows the user to wo

All of this would be trivial for Apple (or someone creating a plugin) to implement. Apple's flagship photography software aperture already allows the user to work with previews while keeping the mega-huge raws on an external device. Instead of an external device, Aperture should just allow the user to point to a service in the cloud. Of course, Apple's iCloud is very little like an actual usable cloud for most pro users.