Deployments all at 0%, all Devices show as Unknown (since Feb 2014 patches)

Our ConfigMgr 2012 instance has stopped deploying software since the last round of MS Patches was applied on Feb 18 (could be coincidence); all the machines come up as "Unknown" in the Deployment status, but they also are showing as Active under Devices. We've restarted the server with no change.

Anyone else having issues with the February patches on CM12? Anyone have any ideas where to start looking (e.g. which of the dozens of logs to start analyzing)?

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- John Straffin, Duke University OIT