The Saudi regime seems very, very brittle. AQ seems to believe so. The US must be ready, in this case to secure the oil fields and facilities if things go badly for the regime. Maybe Jordan, Egypt and the Gulf states could contribute some police and garrison troops if and when the house of Saud collapses.
Pakistan is another case entirely. AQ leadership is enjoying its last redout in their "frontier" region. It has a huge population that cannot really be "controlled" by anyone. Certainly the US does not want to get involved in occupying Pakistan, but AQ must be dealt with and they are hiding in country. The answer here might be to back Musharak for a while, as long as he co-operates in apprehending AQ leaders and operatives. How much co-operation is forthcoming right now is open for debate.