Partly cloudy, with a chance of ...

Each day, it seems, brings more news about the so-called cloud, with the latest, Apple's announcement about its iCloud service, set for Monday. Leaving aside, at least for a moment, our worries about Big Brother, our feelings about there being no real need for this -- and anything else that might darken these skies -- let me ask one simple question: What kinds of files are we talking about here? Would they be like the crappy iTunes downloads? Would they be high res files? Something in between? If anyone has been reporting this, I'm afraid I've missed it.
Any knowledge/speculation about how high (res) the clouds would be much appreciated.
Thanks.
-- Howard