No doubt they plan on retaliating. It will be a lot harder to pull off something even close to the scale of 9/11 nowadays. Plus they just lost a tactical GENIUS in bin Laden. Say what you will about him being a crazy f#ck (and he was) but he was brilliant at what he did. Very doubtful someone with that much influence, money, charisma, ect. replaces him. This was a huge victory on our part. Huge. A lot bigger than a lot of people think.
And for the "skeptics", get over it, he's as dead as disco.