If Oracle had won, this would have a large effect on the entire ecosystem of computers and smart devices. It would have set a precedent that the developers of any API (including those that have nothing to do with Java or Oracle) could dictate what programs can run on said API. Microsoft could use this to say "no FOSS software is allowed to run on Win32 or Win64", making the use of "Secure" Boot an obsolete means of controlling the users.
It's unfortunate that the courts overturned the previous decision, in which they ruled that APIs aren't subject to copyright in the first place. Overturning this decision is almost guaranteed to give API developers a large amount of unjust power over users and developers alike. After all, with APIs now subject to copyright, it's only a matter of time before someone finds a way to use them for nefarious purposes (while of course pretending to be the good guys fighting those evil "pirates").
Oracle is a likely candidate, seeing as how they have already announced their intentions to appeal. "We strongly believe that Google developed Android by illegally copying core Java technology to rush into the mobile device market. Oracle brought this lawsuit to put a stop to Google's illegal behavior. We believe there are numerous grounds for appeal and we plan to bring this case back to the Federal Circuit on appeal," -Dorian Daley, Oracle's general counsel.
It's good to see that Google has managed to convince the court that using these APIs is fair use, if only for now. But, fair use can be a difficult defense for others to raise, given the difficulty in determining whether something counts as fair use or not. While big businesses like Google are able to take the huge financial risk that is typically involved in such cases, most people don't have deep enough pockets to defend themselves with such an uncertain argument.
Also, we all know Google didn't weaken the popularity of the Java programming language, as Oracle has previously claimed. If anything, they brought Java to a brand new platform to be enjoyed by a brand new target audience. The sudden success of Android did, however, make it harder for Oracle to dominate the market with their own smart phones. This lawsuit is simply Oracle's attempt to kill Android, allowing them to take over Andoid's market share (or at least make a big pile of money for nothing). But, having a more popular product isn't illegal (at least as of yet), so they can't sue for being the losers in this market, hence them suing for something else instead.