I wouldn't lose too much sleep over this. They really are not much of a debate anymore anyway, not in the traditional sense. Jim Leherer will probably allow more back and forth than most moderators but it will mostly just be the candidate with uniterrupted time to speak.
Being aware of this tactic of Kerry I'm sure that the Bush camp will have a strategy.
Ala Reagan, "Well... there you go again". (Did I get the accent correct?)