A lot of competing issues in Pakistan:

1) Islamic fundamentalism
2) Fear of Islamic fundamentalism
3) Hatred and fear of India
4) Desire for control/influence over Afghanistan
5) Lack of control over much of their own country
6) Milking the U.S. cow

6) is a constant, so it doesn’t really come into play much. 1) and 4) were the driving factors for awhile. 2) and 5) are taking primacy for the time being, after the Taliban got too big for it’s britches. I think it’s highly unlikely that the recent cooperation represents a long-term shift.