This is a little confusing - Does park hopping use two reservations?
"Magic Key holders who have a park reservation for both theme parks may cross over and switch between parks on the same day beginning at 1:00 PM."
"Magic Key holders who have a park reservation for both parks must enter the first park as designated in their park reservation prior to visiting the other park. At this time, a park reservation is not required after visiting the first park; however, reservation requirements are subject to change."