He's not done. He was basically the exact same player he always was last season minus a few outliers.
I'm writing an article about this right now actually so I've been doing some research, and his rate stats seem consistent with career norms. See no reason he can't bounce back, unless the bat speed thing is true. I don't think any of us know that for sure yet though.
Walk rate is the same as it has ever been. His OBP will always be tied to his BA and last year his BABIP was (coincidentally) around .50 points lower than career norms. But I'm sure that doesn't mean anything, right?
He's hitting line drives at the same rate, swinging at slightly more non-strikes, but not too far from his career norms, and he hit a lot of infield fly balls.
That last part might be tied to bat speed, and I'll try to verify that with video, but there's no telling how much an extra year of aging will affect his swing until we see him. Maybe he's in better shape, maybe he's in worse shape ... but I think his rate stats point to him being roughly the same as he always was in 2011, with worse results.