I believe it’s a sure thing that Greek CDS will be triggered but market will surely sell EUR if/when the annoucement is made. All it takes is one holdout for a credit event to be declared and there are certainly some people positioned to profit.
I suspect the decision will be made shortly after the debt swap is officially unveiled but it may not come until the swap begins but possibly not until March 20, when holdouts aren’t paid.
In any case, we could get hints in the interim.