I believe the ultimate goal for Cloud Computing is development directly on the cloud. This removes the need for 100% of the management over head. SLA really in a cloud should be 100% uptime that is the whole point..
A cool thing about some of the Cloud Hosting environments is that they take advantage of Amazon S3 storage cloud. So its all on the Cloud!
Some leading players:
- VMware vFabric based on SpringSource a Java development framework.
- Mircosoft Azure
Scalable Development Environments
- Ruby on Rails
Example of how easy to install a OpenSource application on the Heroku Cloud