It is easy to create a simple web app that runs in Elastic Beanstalk.
It seems like apps that are designed to run on a local instance of Tomcat and access a database using JPA and/or Hibernate add a level of complexity that is not covered though.
I sure hope I am wrong.
The travel log sample (http://aws.amazon.com/code/1264287584622066) uses SimpleJPA to store data in SimpleDB.