Here's the most important part:
"Important: There have been few significant changes to the effect plug-in API for After Effects CC (12.0), so you shouldn’t need new versions of most plug-ins for After Effects CC (12.0), if you already have plug-ins that work for After Effects CS5, CS5.5, or CS6."
Read the page linked to for details.
Great to know. This has been one of my concerns--ie, having to wait until plug-in vendors catch up before I upgrade. Looking forward to Monday.