It was struck down. Seems you can't exploit children when these children don't exist to be exploited in the first place.
Seemed so to the judges on the Supreme Court. Interestingly, Clarence Thomas joined the lib-activists on this one, while Rehnquist and Scalia dissented. I suspect personal fondness for porn outweighed conservatism there, as it seems to on this forum as well.
But sick adults who want to experience getting sexual gratification by watching digital children get molested can still do so.