Well, tw isn't the only one to think this.  Interesting note on the 1993 attacks:
The Power of Nightmares states that "Al Qaeda", as an organized group, did not exist until the US declared it so and that there was no central effort until the US government stated there was.  For all purposes tangible and not, the US created the group everyone fears.  I'm not sure if you're implying that the US permits the terrorist attacks to occur, but we sure as hell looked the other way when given all of the warning signs on 9/11.  Al Qaeda did not bomb the WTC in 1993.  We somehow credit them, now, for that attack and events before even that.
As far as the prophecy, there have been more than a handful of Bin Laden statements released that stated the US mainland was going to experience an attack.  This has happened for years with no results, although Europe has continued to see such things.  I'm not apt to buy the notion that we're going to be hit in a couple weeks.
But, yeah, I will say that the US needs Al Qaeda just as we needed the Soviets during the cold war.  Even if bin Laden somehow does meet his end, we will continue to hype the terrorist group just as we did the Soviets when we knew they had fallen well behind.  Without the threat, there are plenty of groups that don't get money, plenty of laws that won't get passed, weapons contracts that won't be signed, and the public might begin to turn their attention to better things besides being afraid.  Like, actually questioning the government that is very busy on taking away many of our freedoms.
We don't really need the bin Laden figurehead, but it helps.  Remember the DHS media frenzy?  The VX gas?  The possible bombs in the ports?  The dirty bombs?  Smallpox in the subways?  Poisoning the great lakes and other water supplies with ricin?  Packing Cessnas full of C4?  Stolen crop dusters?  Shoulder-mounted missiles near airports?  The remote controlled planes that would spray anthrax across major cities?  Hidden nukes in shipping containers?  The predicted hack attack on corporations via the internet?  Stolen UPS deliveryman uniforms?  Hijacked, explosive ambulances and firetrucks?  The alerts to cover a safe room in plastic sheeting and duct tape to suffocate--er, save yourself?  
The poison/exploding pens on CNN, for crying out loud?
Everyone bought it, everyone fell for it.  No matter how ludicrous the published threat, the public ate it.  Regular citizens bought gas masks, started carrying guns, and even purchased potassium iodine pills.  From New York City to Nowhere, Nebraska, everyone was trembling, begging for any kind of government help.  In return, a flood of your tax money went to fund organizations that tap 
your phones, monitor 
your e-mail, search residences 
without a warrant, detain anyone they want 
indefinately without any reason, and stage wars to get a US foothold in places we would never have dreamed of obtaining during the cold war threat.  But don't question it -- you'll be aiding 
the invisible enemy or even hurting our troops!  The best part of it all?  Once set into motion, the administration didn't need to place much energy into it to keep the ball rolling.  The public, on its own, managed to perpetuate the fear and manipulate it into the outlandish.  How else did nearly 70% of the public 
believe Saddam was responsible for 9/11?  Stating anything to the contrary, at the time, was simply unAmerican.
9/11 was honestly a dream come true to those that knew there was money to be made and power to gain.  Nothing modifies governments, changes people, and brings in the cash like fear.
Your 24 hour news channels have displayed the national terror alert level color nearly once every minute for more than five years, now.  The scrolling ticker at the bottom of your screen has not gone away since the morning of 9/11/2001.
Oh, yeah, you're not any safer today than you were on September, 10th, 2001 for all of the airport precautions that were put into effect and then just as quickly removed.  What is the real reason, do you think, that the fear was hyped up?  Do you think, maybe, that you've all been taken advantage of?