I doubt there will be “peace”. In 1990s when TNSM declared “Sharia enforced” in Swat (?) it wasn’t a retaliation to any “foreign” forces, grenades/bombs were thrown in masajid across the country before 2001, sectarian killing never stopped (for last few months surprisingly its low 
). Before Musharraf resigned Pakistan was target because “they” were mad at him, but after he resigned the situation is still the same.
The terrorists who are demanding that US leave is just an excuse to carry out what they want, just like they are using Islam as their cover this demand of “foreign forces leave” is just an excuse.
Though “Taliban” are unlikely to “take over” but they are likely to carry out their activities with or without foreign forces.