My wife ordered a gift for her Mom from Michigan on December 5th with priority mail delivery to Pennsylvania. It was tendered to USPS on the 7th with delivery expected by the 11th. As of the 11th it has been setting in Michigan with no movement and no updates.
I ordered a movie on the 11th from Indiana to be shipped media mail. It was tendered to USPS on the 12th with delivery expected by the 17th. It has been setting here in Pennsylvania since the 15th, again no movement, no updates. Being as this is media mail I doubt it will arrive before Christmas.