Wither the CIO?

Another topic of discussion at the Bathwick session yesterday was how the emerging world of SaaS and Cloud might impact on the future of CIO roles. In a world where technologists are no longer required to purchase what are fully-functioning business services, why have a CIO?
For me, the value in an internal group to manage business systems comes from having the oversight of what is happening across the enterprise, and how what the business does marries to the technology services it uses. Data and process elements of Enterprise Architecture become core competencies, along with procurement and (most crucially) supplier management..
Unfortunately, whilst to a savvy IT person the above should make perfect sense, it doesn't really sell itself to someone outside of our world.
Keeping the CIO role is as much as anything about selling it to the people who make the decisions. That has to happen at many different levels, but for me at the moment if summed up to my business as moving my department from trying to be experts in technology to being the experts in how our company uses technology.