It is coming, just like they say it is. The APA will remove it as a disorder, and then it will cease to be a criminal act. Perhaps not in our lifetime, but in our children's lifetime.
The fearful thing about this whole thing is that, once the common man has lost all reason to have faith in the establishment, such as trusting that laws are just, what will prevent him from resorting to "homemade" solutions to his problems? If he cannot look to the laws of our states to save his children from predators, he must resort to his own forms of justice to keep them safe.
I really have trouble seeing this happening. Beyond the whole "disorder" issue, one of the big reasons that it's a crime is because children are considered to be incapable of informed consent.
To legalize this vile behavior they'd have to pretty much revoke the entire concept of childhood and the concept that kids under a certain age do not have the necessary judgement and experience to make major life decisions. Kids declared able to give "informed consent" to sexual behavior with adults would also have to be allowed to vote, marry, serve in the military, etc.
There will always be a small subset of nutjob shrinks that try to argue this, but hopefully common sense will prevail.