I talked to folks at the company Makara, which has its general release today. They provide a kind of PaaS middleware for clouds: application management software for web applications (currently Java/JBoss and PHP) that creates instances you can schedule and run on public cloud services or your own virtual systems.
Like some other services (notably Heroku), Makara can automatically scale up servers, do automatic failover, and other things that take cloud management off the shoulders of the users. Makara's promise is that you can move traditional, locally hosted applications into their cloud platform with no extra programming and minimal fussing with operations.
What I found particularly interesting is their performance monitoring. It offers quite fine-grained reporting: you can look at each session and see how much time you spent in the web server, how much in the database, how much traversing the network, etc. Some clever instrumentation is in play, which unfortunately Makara can't talk about while they have a patent pending.