The fair use decision was wrong. It relied on a fundamental misunderstanding of the term transformative where the use of the code was considered rather than merely the implementation. So Oracle has a huge case here.
Moreover, practically it doesn't matter. Even if fair use is established in this case, the door has been left wide open to hordes of API copyright trolls. If you thought patent trolls were bad, you ain't seen nothing yet.
If you care about the economy, the only sensible outcome would be that API surfaces aren't subject to copyright. Sadly the horse has bolted a long time ago.