These are exercises to test intercept and communications techniques in order to test readiness in case of another attack. Usually very limited comms - typically a fixed wing a/c will travel along a certain predefined route, and a couple of F15s will be scrambled to escort the 'intruder' off.
There have been many such FV (Falcon Virgo) tests since 9/11. From what I saw of the announcement, it's not really different from any of the other tests in the past.
It's not unusual to hear comms on 139.7 AM with Huntress, and possibly 1 or 2 other freqs as well, depending on what the plan for the exercise is. Sometimes a USCG helo is used as the 'intruder', and they'll use one of the VHF marine channels (I've forgotten which one) for their comms. 73 Mike