Glad to see the free service and a dedicated ruby blog.
I successfully deployed one of my apps to AWS via Elastic Beanstalk with no issue, while previously I used Rubber to manage my deployments. I think I like beanstalk because of its zero-cost and simplicity. Though I haven't figured out how to use private gem.
I'm loving Ruby support in Elastic Beanstalk so far. My biggest complaint is that there isn't really a way to launch worker processes like resque or delayed_job. A separate autoscaling group that can run a rake task would be nice. Support for a Heroku style Procfile would be especially nice.
You could probably use 'container commands' to start/stop worker processes after each deployment. I'm only reading the Elastic Beanstalk docs for the first time, so I haven't tried it myself - but it looks like it could be the right solution: