Short term no. Obviously the pics are out there, the damage has been done. The tiny fine imposed (a mere swat on the wrist) is absolutely no deterrent when laid against the huge profits the magazines already made from the pics. And someday in the future, the pictures will no doubt resurface.
But long term, the ruling does help. It legally establishes that the royals have the right to privacy in certain circumstances, and editors will have to use that when debating whether to publish future questionable pictures. Some will, of course, but the future punishments can be harsher because of this ruling.