The assasination may have been a Bush operation. U.S. Intelligence cells could have set up the hit working with extremist groups.
The motive would be the perpetuation of the tremendously profitable "war on terror." Keeping it on the front burner as opposed to the climate change issue.
Keeping Musharraf in power and Pakistan divided is in the interests of the Bush regime. Its called Divide and Conquer. Its the first rule in the Bush rule book of how to rule.
Bush doesn't want to be ignored and ridiculed. That hatemonger will do anything to maintain his rule.