No, not authorized is a lighter ruling. It means tomorrow congress can pass a law explicitly allowing it, and there would be no problem cuz it wasn't ruled unconstitutional.
Not authorized isn't a lighter ruling, it's a very damning ruling against the NSA, and it's the only ruling that can be made in this case simply for the reason that there was no law on the books where Congress gave authorization for the NSA to operate like this. To put it succinctly: The NSA was ruled to be operating outside the law... which effectively makes them criminals (won't be holding my breath for any actual prosecutions, though).
Now, if Congress goes back and creates a law that Authorizes the NSA to operate in this manner, then the issue can be brought back to court for Judgement to be made on the constitutionality of the law. Then that verdict will hold a more permanent weight on the future of government surveillance and the kind of laws Congress is able to write around it.
The cost of feathers has risen, even down is up!