Well, there have long been sites like Flickr, but the IT industry loves to sell us old ideas under new names. I think that internet-accessed storage is a convenient way of sharing, or getting multi-location access to data. If you have the bandwidth, it also makes a great secondary backup system.
I would never, ever, never use it as a either primary storage or primary backup. Not personally, and not professionally. In fact, I would accuse IT directors that sign up to the current cloud fad of being criminally negligent!
There are all kinds of ways that you can loose access, probably temporarily, but also permanently, to data stored for you by a third party. It doesn't matter how big the service provider's name is: even the biggest are not immune to technical issues, and some pretty big companies suddenly don't exist any longer. I'm not even going to get started on privacy and security issues. To be honest, I'm not well-informed enough about that anyway, partly because I think it is such a bad idea in the first place.
Use the "cloud" for convenience and sharing, not for secure data storage. Your data is secure when it is on equipment/media that you own, that you are responsible for, and that you know, and control, the physical whereabouts of.
If I were still an IT manager, I know exactly what my response to a cloud salesman would be. And I'm not usually a violent person :lol:
Another big practical cloud issue, for us, is bandwidth, with the data speeds and caps we have here. Keeping this week's pics/music/docs up to date might be feasible, but uploading that first terrabyte or three would be impossible.