Bob doesn’t necessarily define it but he gives some of the characteristics that help define cloud computing. As I opined tonight (quite passionately at times), hosting is not cloud computing, virtualisation is not cloud computing and SaaS is not cloud computing. They can all be delivered using a cloud computing platform but to use the terms synonymously with cloud is wrong I think.
One opinion I heard tonight was that anything delivered through a browser is cloud computing. No wonder all the consultancy firms are dashing around offering opinions and selling their views 🙂