The @osintegrators pushed an interesting article up comparing the deployment steps you need to take to get a war file hosted on :

• CloudBees
• Cloud Foundry
• Heroku
• Openshift
• AWS Elasic Beanstalk
• Windows Azure
• Google App Engine

The nice thing about the article is that it’s mainly just a bunch of screenshots, so with a quick scroll and an even faster glance, you can get a good idea of the basic steps that are required to get your app up, running and hosted in the cloud.

A quick conclusion? It looks like the AWS Elastic Beanstalk is pretty convoluted. The most seamless? It looks like Microsoft's Azure. Of course, looks an always be deceiving.

One solution that they missed is Jelastic: http://jelastic.com - this one is quickly gaining traction in the Java world. For example, it got the mail Java award of the year - Duke's Choice award as Technology Leader at JavaOne: http://blog.jelastic.com/2012/10/01/the-dukes-choice-awards-2012-we-won/

This is companion material to my column on InfoWorld linked from here http://osintegrators.com/freakingPaaS.  In reality Azure's tooling is broken on Linux and it deploys your whole Tomcat.  CloudBees and CloudFoundry were the simplest but there are other factors to consider such as SLA, security certs, etc that we covered in the article.