The Golden Copy of the GDrive is as much of a pipedream as the the celestial jukebox of late 90ies fame. People want to have, to own, to keep. That’s why even arcane tools like Download videos from Youtube, Google Video, Metacafe and iFilm are quite popular. That’s why record sales will never completely disappear (download vouchers for DRM-crippled audio files are a decidedly unsexy present). And that’s why - nevermind any privacy issues - the Golden Copy residing on a central server is a tinny concept (a backup is something different, and not what we’re talking here).
Not to forget: ideas like that seem feasible, because storage is becoming bigger and bigger and cheap and cheaper. In about 5 years, a top of the line HD should store about half a PetaByte of Data. Great. And now show me the public network, seemlessly handling just several GB - ubiquosly.