EBS just recently added support for Node. It's definitely on the list as the next PaaS to try out. AppFog is another one that we've done a JVM deployment to and like a lot except for the fact that it just feels very alpha quality. Their website is painfully slow and under documented and the 'af' command isn't nearly as cool as just doing git deploy remote master.
I should also add that one thing that Heroku did get 100% correct is the heroku logs -t command (aka: tailing the logs). Nobody else does that one quite as well.