Oh, Jerry Sandusky. Don't bother regretting that you didn't take the stand at your trial. It wouldn't have changed the outcome. The sad, hard truth is that it's the rare defendant accused of child sex offenses who can help himself by testifying. The cold hard truth is that juries come into these trial expecting to find the accused guilty. They may not say it, but that's how they feel. They expect to believe the accuser. They start from a place of believing that no one would lie about this stuff. It is the rare, rare case where the defendant can convince them otherwise.
The way to win these cases is to make the jury doubt the accuser. Defendants are in a no-win situation. Because even though a jury is instructed not to infer guilt from the defendant's refusal to testify (aka his exercise of his 5th Amendment right), deep down we know that they do. But they can't help themselves by testifying, either, because any denial will just sound like what a sex offender would say. It's really hard for anyone, even the most earnest, innocent person to sound convincing when denying allegations of child sex abuse.
Given the sheer number of accusers against Sandusky and the testimony of the graduate assistant coach who says he saw a sex act occurring, there is almost no way he could have helped himself by testifying. Denying that many accusations is nearly impossible. The defense attorney really is the best chance for winning a child sex case, not the defendant. The defense attorney would have to create a compelling, coherent story about why so many allegations were made. It can be done, as we should all remember the day care trials of the '80s. Dozens of children were led to make false accusations, a fact that defense attorneys were able to set out for courts in many of those cases (unfortunately after people spent time in prison). But no defendant, no matter how compelling, could have convinced a jury of the falseness of those accusations.
And neither could Jerry Sandusky. Which is why he shouldn't waste any time or emotional energy regretting his choice not to testify. No one can talk his or her way out of accusations like this.