Thanks for letting me know! I got the impression hosting would become a paid service from this paragraph in the announcement email:
"As part of the AppFog family, Nodester users will now be able to use the same PaaS for their Ruby and Java apps that they use for their Node apps. It brings the serious support and operational excellence of AppFog to our users, enabling them to run production and enterprise workloads on their developer PaaS. Perhaps most significant of all - it allows Nodester users to deploy apps to a wide range of different IaaS providers - at a highly competitive price" (emphasis is mine).