I found this item in The Reg:
Cloud computing has its very own catch-22. If we can tap into the cloud, grabbing our compute resources on the fly, we can free ourselves from the old school software licensing models. But old school software licensing models may prevent us from tapping into the cloud.
"The dirty little secret of the utility computing business - and now, increasingly, the cloud business - is that if the software licensing model doesn't catch up, people will either be forced to pull from the open source world or the whole idea is going to drop dead under its own weight," AT&T cloud evangelist Joe Weinman said today during a panel discussion at Structure 08, a mini-conference in San Francisco dedicated to all things cloud. "The cost savings will not be there, and the whole idea will never materialize."
This isn't a “dirty little secret”, it's the fundamental reason why cloud computing works – commoditisation of computing power is only possible if the underlying elements are commoditised - free, in other words. It's yet another reason why open source will become the norm for all computing infrastructure, at every level.