What then are the extra services that takes cloud computing one step beyond traditional hosting? Here are a few:
- Load balancing: a flexible set of computing resources can all be transparently load-balanced behind a virtual router.
- Content Delivery: the work done by a content delivery network can all be done transparently by a cloud computing provider, such as Amazon CloudFront.
- Failover: if your data is load-balanced between multiple data centers, and one data center goes offline, a cloud computing provider should be able to failover the traffic from one to the others. (If they can't now, they should provide this service. :))
- Scalability: the number of compute resources used should automatically scale up or down based on demand.
- Tooling: with the advent of mainstream cloud computing providers, the tooling has improved tremendously. For example, Windows Azure tools allow developers to test everything out locally and easily deploy to the cloud, and thus enabling people to easily build scalable services.
Last, but not least, everything above is geared towards businesses. What about cloud-computing for consumers? In that space, it's the applications that drive a platform--applications such as Microsoft's Live Mesh, ubuntu one, etc.