Activision and Sledgehammer Games have confirmed today that you will be able to transfer your Call of Duty: Advanced Warfare multiplayer stats between Xbox 360 and Xbox One or PS3 and PS4.
All of your Multiplayer stats and gear are shared within a console family (Xbox 360 <-> Xbox One or PS3™ <-> PS4™) and will be waiting for you when you transition to next-gen
This works both ways, meaning if you rank up on PS3, then play on PS4 – your stats will transfer, and, if you play on PS4, then go back to PS3, your updated stats will be there. (Same for Xbox platforms.)
SOURCE: Advanced Warfare