The ruling is on a matter of law. It isn't a ruling on the guilt of GeenStijl, or anyone else that shares links. It gives the referring court instructions for how to interpret the EU copyright directive, specifically on whether the criminal act of communicating a work to the public without the consent of the copyright owner had occurred.
The Supreme Court of the Netherlands (Hoge Raad) asked the Court of Justice of the European Union (CJEU) to rule on in what circumstances should sharing links to infringing content be considered a "communication to the public", with specific attention to how the decision is effected by the prior availability of the content and whether the person sharing the links knew the content was infringing.
The ruling of the CJEU was that when somebody knowingly shares links to infringing content for money, it should be presumed that they knew the content was infringing. This is not strictly an answer to the question, IMO, but it does establish criminal intent.
It is being generally reported that commercial infringing linking has been generally ruled to be "communication to the public". I don't think that's the ruling, although the part of the judgement that isn't the ruling does say that. It would be interesting to know whether the whole judgement, or just the ruling at the end, is considered binding. I tend to assume the later, since the ruling is a repetition of the last paragraph of the judgement, and why would that happen if the judgement was binding?
(Edit: Removed lots of unnecessary words.)