ISVs that leverage the APIs provided by Amazon, Iron Mountain, Nirvanix and others are the companies that will play a large part in making cloud storage the monumental success that many are predicting. For example, I recently met with Recentris, an ISV that makes Electronic Lab Notebooks for companies that need to track research. They leverage Iron Mountain's API and cloud to provide a mechanism for their clients to archive and store notebooks as they age out. Leveraging the cloud they can manage retention and immutability for their customer's data.
I'm not sure how many readers of Network Computing would have even known about Recentris but that's the point. There are thousands of ISVs out there and as they start to add cloud storage functionality to their application, its use will grow. The application itself can determine how old the data is, when it was last accessed and the various meta data parameters about the data. These applications can provide the most accurate use of an archive tier that we have seen.
In speaking with ISVs, the time it takes to integrate to the API set is minimal, often less than a few weeks. Of course, there is more to it than the API integration. There is the presentation of the option within their GUI and other development concerns, but overall they can leverage the backend capabilities of the cloud provider to write such difficult features themselves, such as provisioning, WORM, retention and replication.
Certainly the more traditional uses of cloud storage (backup and archive) will continue to be the big drivers in the market. However, as cloud storage becomes an option to an existing application, especially ones that are not from traditional storage applications, its adoption will accelerate at an even faster pace.