According to the CIA, it looks like those of us who suspected Al Qaeda and the Taliban as the main culprits in the Bhutto assassination were correct:
The CIA has concluded that members of al-Qaeda and allies of Pakistani tribal leader Baitullah Mehsud were responsible for last month's assassination of former Pakistani prime minister Benazir Bhutto, and that they also stand behind a new wave of violence threatening that country's stability, the agency's director, Michael V. Hayden, said in an interview.Offering the most definitive public assessment by a U.S. intelligence official, Hayden said Bhutto was killed by fighters allied with Mehsud, a tribal leader in northwestern Pakistan, with support from al-Qaeda's terrorist network. That view mirrors the Pakistani government's assertions
Those who thought it was the Pakistani government's fault aren't totally wrong, however. The LA Times reports:
One former Pakistani official, however, cautioned that even if Mahsud was involved, that did not mean that elements in the Pakistani army or intelligence agencies did not play a role in the slaying, even if only to look the other way or help stymie an investigation.
That's my conclusion: Al Qaeda/the Taliban (largely one and the same in Pakistan) were responsible for Benazir Bhutto's assassination, with possible involvement (active or passive) by elements within the Pakistani army and/or intelligence services. Complicated, murky, dark, dirty. Maybe there should be a sequel to Syriana called Pakistaniana?