They are marketing cloud storage as a way to share data with other people, so there is no reason to worry about it being taken offline as its not designed to be used as primary or even backup storage. If they limit the file types to media and office-type documents then they aren't really offering anything new since you can already do that with their other services. Still, it would be nice to have a central location to manage all of your online files. I'll give it a try, I just won't upload anything incriminating.