Sysadvent features a puppetlabs sponsered article (yes, honestly, check the bottom of the page!) about chef enterprise getting push support. It is supposed to be included in the open source release in Q1/2014. With this change you can use a push jobs cookbook to define jobs and an extended "knife" with new commands to start and query about jobs:
knife job start ... knife job listand
knife node status ...will tell about job execution status on the remote node. At a first glance it seems nice. Then again I feel worried when this is intended to get rid of SSH keys. Why do we need to get rid of them exactly? And in exchange for what?