what he wants is idisk which was available in mobileme and requested by many people for icloud.
the thing is that apple almost gives you no reason to have a drive since you can save music, books, notes, email, contacts, documents, pictures, games
the only thing missing is video... this is for non pro users... for pro users the idisk would be better but apple cares more about profit lately. pro users seem to be less of an important crowd each new os. the best thing to do is to get an external drive since dropbox requires pay unless you want 2-8gb