Today I read a blog from David Linthicum in which he said that the corporate datacenter is safe from cloud computing because issues around compliance, privacy, fear, and control will cause companies to want to keep their computing in-house.   However, I'm not sure that this is an us-vs-them issue, and there is a good reason that the corporate datacenter will stick around for a long time: it's cost-effective, though only if well-run, and large enough to provide the economies of scale that make it so. What cloud computing will do is provide a benchmark for the cost-effectiveness of the internal datacenter by providing an alternative.

I think the discussion on whether cloud computing will kill the datacenter should be reframed: it's more like "The king is dead. Long live the King!"  Once the hype of cloud computing has been overcome, I think it will be shown to be a set of *technologies* that enable a set of *services*, rather than a specific set of branded products as it is being marketed now.  And those technologies are just as useful inside the corporate datacenter in a "private cloud" as they are in a service provider's datacenter serving up a public cloud.
The issues around compliance, privacy, fear, and control will have to be played out inside the enterprise just as well as they are in the public forum as these technologies do actually provide advantages no matter where they are applied and will create revolutionary change in any case. What are these technologies?  Virtualization of compute, I/O, and storage; pay-per-use microbilling; IT workflow automation; and application template libraries.  If IT staff think that their jobs are safe from radical change just because their company isn't outsourcing its computing to the cloud, I think they'll be in for a surprise because these technologies - collectively "cloud computing" - will impact them anyway.