Cloud computing in the enterprise is a favorite lunch topic of myself and a few friends. It comes up occasionally and is always entertaining (at least for me) to position ourselves on why it will, or will not, become in demand. In this particular context, we are looking at provider hosted cloud computing. Meaning the 'cloud' is hosted outside the security boundary of the enterprise.
I found this article by Russell Jones, titled "Executives Avoiding Cloud Computing In Droves" that does an excellent job encapsulating several reasons why cloud computing will be a hard sell for the enterprise. They are all valid reasons: security, data ownership and control. Though there are probably a handful of mission critical applications already being consumed as a service (e.g. payroll).
I'm not so sure its actually a 'hard sell' as it is that enterprises tend to move slower on adoption. The big adopters of the cloud are going to be smaller customers. Your small businesses who don't have the resources to provide the necessary application infrastructure themselves. An example might be a manufacturer who uses Quickbooks needing to integrate PO's between distributors, or distributors needing to manage PO's and Inventory between retailers. Amazon Simple Queue Service is a cloud based implementation that allows integration with all parties without requiring 100% uptime of any actual participant. That's the platform that will enable smaller business grow more readily to meet any business demand, or requirements, without significant capital expense or operating costs. Need to exchange messages greater than 8K in size? Then maybe Amazon's Simple Storage Service is a better fit, or more likely a combination of the two.
Of all the points in the article, the one about availability jumped out at me. This one just seems more of a scare tactic than any of the other reasons. Outages occur, even within the enterprise. Even with big enterprises. However, within an enterprise, your more likely to have access to the people who now how to plan for, and manage, these events. But they still happen. A smaller company is much less likely to have these kind of resources. In this case, a hosted solution is likely a better option for a small, to medium sized, business.
The only other thing that jumped out at me was the citation that cloud computing was the last thing on a CIO's list. I'd whole heartedly agree with that statement. However, I'm pretty sure that managing/reducing the cost of IT is not low on that list, and is likely very closer to the top. Opportunities for reducing those costs don't come around everyday and the cloud might just be one such opportunity.
No, the article for me anyway, still shows the cloud in an interesting, and exciting light. Is that to say that everything belongs in the cloud? Not today. Maybe not tomorrow either. Are there still kinks to be worked out? You bet! That's not to say that it won't be fun to figure out what exactly we can, and can't, successfully run in the cloud!
 'Cloud' computing may already be showing up in your enterprise today. Your very own private cloud. As an application owner, you may find that you are already outsourcing services such as storage, data access, security, etc, to teams that don't directly report to your cost center. Your already relying on 'outside' resources to manage mission critical pieces of your application. This application operation experience is not likely to be that much different, in theory, between hosting services locally vs. the cloud, except you've got an extension to call if things are not running right. This is an oversimplification, but something to think about.
 Article showed up in Arnon's Shared Items. Arnon's Shared Items is like a firehose of interesting, and industry related, topics. There is some overlap with other existing feeds I subscribe to, but this is usually a good launch point over coffee, during a break, or whenever I've got free time.
 There are still going to be development costs, and these are not necessarily cheap.