Expect a whole series in mid to late January (typically). A good place to look at when these things take place, just look at the past COOPs and see when they were run. This would give you a good barometer of when you can expect a COOP. With this said, even the COOP managers do not exactly know where a COOP is going to happen. They usually just arise within a week's decision to run one.
Welcome to the addiction! *smile*
Kurt