It's almost unfortunate that early generations of Software as a Service were strongly influenced by small-and-medium business (SMB) needs for simplicity and ease of use. When that origin is combined with the limited feature set and shallow customization tools of many consumer-grade Web applications, people can easily underestimate the true capability of cloud-based applications and platforms.

When you look at the most pressing needs facing enterprise IT professionals -- to engage business units in more of their data-related tasks, to provide strong policy leadership in information security and business process governance, and to ramp up their initiatives in data analytics and search -- it's really quite clear that SaaS and PaaS are not merely capable, but ideal solutions to these needs.

• When software as a service is delivered with powerful and accessible customization tools like salesforce.com’s programmable workflows, Apex Code for custom logic and Visualforce for user interface design, the business unit takes more ownership of the application and adopts the new tools far more broadly and rapidly.
• When application usage is observable through a service provider’s dashboards and other assessment aids, there’s far better visibility into who’s using different types of data in various ways.  
• When a platform as a service makes it easy for applications to share data, conveniently but selectively, the most difficult and brittle parts of a business analytics initiative are handled with ease and flexibility, right up front.

I've made this case for the enterprise readiness of the cloud in this 4-minute video, as well as in a more complete white paper available for free download. Please tell me what you think.