Both advocates and opponents of Bush-era interrogation techniques like waterboarding have been quick to spin Osama bin Laden's death as a vindication of their position. (Donald Rumsfeld has even been recruited as an unlikely ally for the opponents.) Part of the problem is that the information on how the intelligence leading to bin Laden's discovery isn't quite conclusive. On the one hand:
In a secret CIA prison in Eastern Europe years ago, al-Qaida's No. 3 leader, Khalid Sheikh Mohammed, gave authorities the nicknames of several of bin Laden's couriers, four former U.S. intelligence officials said. Those names were among thousands of leads the CIA was pursuing.
One man became a particular interest for the agency when another detainee, Abu Faraj al-Libi, told interrogators that when he was promoted to succeed Mohammed as al-Qaida's operational leader he received the word through a courier. Only bin Laden would have given al-Libi that promotion, CIA officials believed. If they could find that courier, they'd find bin Laden.
The revelation that intelligence gleaned from the CIA's so-called black sites helped kill bin Laden was seen as vindication for many intelligence officials who have been repeatedly investigated and criticized for their involvement in a program that involved the harshest interrogation methods in U.S. history.
On the other hand (same AP story):
Mohammed did not reveal the names while being subjected to the simulated drowning technique known as waterboarding, former officials said. He identified them many months later under standard interrogation, they said, leaving it once again up for debate as to whether the harsh technique was a valuable tool or an unnecessarily violent tactic.
Here's the Times story,which gives a similar account:
The raid was the culmination of years of painstaking intelligence work, including the interrogation of C.I.A. detainees in secret prisons in Eastern Europe, where sometimes what was not said was as useful as what was. Intelligence agencies eavesdropped on telephone calls and e-mails of the courier’s Arab family in a Persian Gulf state and pored over satellite images of the compound in Abbottabad to determine a “pattern of life” that might decide whether the operation would be worth the risk. [...]
As the hunt for Bin Laden continued, the spy agency was being buffeted on other fronts: the botched intelligence assessments about weapons of mass destruction leading up to the Iraq War, and the intense criticism for using waterboarding and other extreme interrogation methods that critics said amounted to torture.
By 2005, many inside the C.I.A. had reached the conclusion that the Bin Laden hunt had grown cold, and the agency’s top clandestine officer ordered an overhaul of the agency’s counterterrorism operations. The result was Operation Cannonball, a bureaucratic reshuffling that placed more C.I.A. case officers on the ground in Pakistan and Afghanistan.
With more agents in the field, the C.I.A. finally got the courier’s family name. With that, they turned to one of their greatest investigative tools — the National Security Agency began intercepting telephone calls and e-mail messages between the man’s family and anyone inside Pakistan. From there they got his full name.
In truth, there's not really enough here to prove either side's point. This was a long and complex operation in which a variety of interrogation and intelligence gathering methods were used. Torture didn't "get the job done." It's clear that at no point did a waterboarded suspect yell out, "Osama's in Abottabad." On the other hand, it seems quite possible that some useful information may have been gained through interrogation methods opposed by civil libertarians. Whether or not bin Laden could ever have been captured without these methods seems like a pretty impossible thing to prove, either way.
Also check out Blake Hounshell's guide to some of the other post-bin Laden spin floating around the mediasphere.