Pivotal has developed and open sourced some new components for Cloud Foundry to make deployment a lot easier with some new options and really short commands for pushing your applications via Maven or Gradle:
$ mvn clean package cf:push
$ gradle clean assemble cf-push
This blog post on Pivotal's blog shows you how to use the Gradle and Maven plugins in your own project. If you don't want to bother setting up Cloud Foundry on your own service provider, you can use run.pivotal.io.
It would be interesting to know what PaaS has the best support for Java build systems and other important tools.