Recently on the Byte and Switch forums there has been a bit of curmudgeonousness going on. We jump all over people for using terms like Cloud Storage, instead of Grid Storage, or Cloud Computing, instead of Web-Based Application. Maybe it's the economy that has everyone in such a foul mood, but there is a need for this marketing speak because it defines an incremental step forward in technology. While I'll admit that most of the time the technological step does not justify the marketing hype, sometimes it does.
We need companies and individuals trying new stuff. Innovation typically comes in baby steps. Most "new" things are just incremental upgrades to what we tried last year. They may be minor tweaks to a phrase and a technology, but it might be that final tweak that pushes the technology into the mainstream.
Take a non-storage example: Apple's iPod. Now all of us stalwart technical people saw that when this thing first came out it was basically an MP3 player with a slightly simpler interface, a larger-than-normal song storage area, and an integration to this weird application called iTunes. The curmudgeon said: "This is basically my Sony Walkman, don't need it. Why would I want to be forced to buy all my music from one place?" Years later, the thing not only dominates the portable music player industry, but it also is one of the dominant forces in the music industry itself. Try to buy your kid something that is "just like" an iPod and see how fast it is thrown back at you. Ask Microsoft.
Cloud Computing and Cloud Storage is much the same thing. They are terms describing an evolving set of technology and marketing to try to deliver a solution. Yes, they are the evolution of software as a service, Web-based applications, storage as a service, etc... If you look at the components of each of those technologies you will certainly see parts that have been reused into what we see in the evolving cloud markets.
You will also see unique capabilities like location-aware storage. As Byte and Switch blogger Howard Mark correctly points out in his recent post and I indicate in our Cloud Storage White Paper, a key differentiator of Cloud Storage is its geographic dispersion of data. As for Howard's request for a single definition for each so we can keep the suppliers from marketing scooters as motorcycles, often that definition is left to the eventual market winner.