I don't know if I'd say the establishment of the feasts of All Saints and All Souls (and Christmas, for that matter) were deliberate moves to replace pagan celebrations. These celebrations came from local churches, and quite obviously grew from pagan feasts that were part of local tradition. The celebrations grew in popularity as centuries went on, and were eventually accepted by the church as official. By the time they became "official," the pagan roots of the feasts had long been forgotten. It seems to have been a process of natural growth (folk process???), not establishing something to replace an older tradition.

-Joe Offer-