It's really sad. I really liked watching him play earlier in his career with Seattle.
I think he is done due to the hip injury. I also think the Yankees will settle with him and pay a portion of his remaining contract if he retires early. That way, if he ever does consider coming back, the Yankees would maintain rights and trade him. (Something is better than nothing)
I just can't imagine him working his way back to be a DH at this point in his career.