Bhutto said at the time that the assassins could have come from "a gang from the Afganistan warlord Baitullah Mehsud, or Hamza bin Laden the son of Osama bin Laden, or the Pakistani Taliban in Islamabad, or by a group in Karachi."

This should put conspiracy theories to rest, although I frankly don't understand why the Taliban would want her dead. She used to finance them.

In a Prescient Interview, Bhutto Fingered Assassination Suspects | Threat Level from Wired.com