Jeep Repair: Jeep cherokee, air conditioner compressor, alignment shop

Question
recently I had my tires rotated. Now at 55mph
I get a front end shimmy that goes away at 65mph. also, I'm getting a horrible squeak from the pully when I turn on the AC or defroster.  

Answer
Take your Jeep to a front end alignment shop, have them put it up on the rack and take a look.  I would suspect the front end needs aligning but you might have something badly worn that needs replacing.
The squeak is your drive belt, it probably is getting hard and needs to be replaced before it breaks.  You also might have an air conditioner compressor that is getting bad and this is the first sign of trouble coming.