the key thing to watch for will be over the next few days - if we see a disruptions in the suicide attacks. if the leadership, perhaps all the way to the top, was wiped out - there will be dissaray in the short term planning and execution of new suicide attacks.
No, it works backwards from logic. If we got him, they'll lash out with suicide attacks (from that pool of those prepped to go, anyway)...unless he's become so unpopular that even Al Qaeda celebrates his demise.
Keep in mind that Zawahiri's letter warned him against the very things that he's done (e.g. bombing a wedding in Jordan) to make himself so unpopular. He's attacking fellow Muslims to such an inexcusable degree that his own family has disowned him.
If he's gone, then look for Zawahiri to make it clear that he's in control.
If not, look for Zarqawi to make some sort of public statement (it won't be the statement itself that matters...but he'll have to show his followers that he's still alive).