This is only going to get worse in the next few days. No doubt her supporters, understandably, will want revenge.
I don't know if the Islamists did this or not. I think it as likely that Musharraf could have ordered this or worked through secondary channels to have this done. Whoever is responsible, Pakistan is headed for some major trouble which will definitely spill into other parts of the region thus pulling in India, Iran, China and Russia. The U.S. won't be able to stand on the sidelines on this one.
Lord have mercy.