Re: field of use restriction
Not only is Harmony not licensed as a Java implementation, Google have actively fulfilled the only restriction Sun actually made on non-licensed versions, that they don't call it Java. That's why there are no contractual infringement claims in the case, you can't hit non parties with contract claims.
Oracle have had to rewrite copyright law to make any sort of case (they really should have seen the patent suicide coming) and they've done it in a way that even if they were 100% correct and justified, the claims must fail or risk massive collateral damage to the entire software industry.
One reason US software copyright law seems so perverse and unfair is that the consequences of being more like traditional fields (literature, film etc) would be crippling to the industry. Google walked right on the edge of what's legal, don't expect massive penalties if they overstepped. Oracle need to redefine the law or they can't win enough to bother. If Oracle big we *all* lose.