They already have a cloud storage system, it's just nothing like Dropbox... Given Apple's intent to keep things simple and to hide the file system from users, I highly doubt that something like what you're asking for will ever happen...
This isn't to say I wouldn't want it, in fact I'd love something like that, it's just not a realistic expectation in my opinion.
Pietro
While I half-agree, the amount of professional Apple pundits that have mentioned the lack of a dropbox-like functionality is growing all the time. I have listened/watched/read so many shows & articles in the last few months from pundits saying how Apple's iCloud service is much too simplistic so ends-up being MORE confusing and complicated to use, especially for non-techie users, thus defeating its usefulness, when the other mainstream providers (eg. GDrive, Dropbox, SkyDrive [renamed OneDrive in a month!], etc.) are offering a much more simple docs folder users would appreciate a lot more.
...they can't all be wrong, and I agree with them.
Hiding the file system is silly, as almost all users folder-ize their files on their Macs, so they can group by topic/project/company or whatever (eg. "Banking" folder, subfolders for "Bank 1", "Bank 2", et al). Those folders usually contain a
mixture of file types too, so when one needs to look into one of them, we want to see and have access to ALL the files in the folder, not just .pages, .numbers, or whatever, ones that happen to sync over Apple's iCloud sync.
To be fair, I think the reason they have failed to either increase the free iCloud storage (and paid tiers above 50GB), is because Apple have not built-out their datacentres enough yet, so they are playing catch-up to the likes of MS/Google/Amazon, et al. When they appear (plus they fix the Core Data sync service for non-Apple app data syncing), then we'll
finally see some improvements from them in this area. Fingers-crossed, at least, otherwise they're gonna fall behind in the online services battle, especially those that also offer better cross-platform compatibility.
