I don't know if "congratulations" is exactly the right word, but I think it's important to respect those who show up, take the test, and conduct themselves honorably.
Sonne's accusations notwithstanding, we don't do this because they're "the enemy." The MDC isn't an excuse for us to ridicule people we disagree with. JREF has this challenge for a reason - to promote critical thinking and scientific evaluation of supernatural claims.
Those who take the test, by and large, are not the Sylvia Brownes of the world. The people who go through with the process genuinely believe they have the powers they claim. They're not bad people, they're not frauds, and they don't rape puppies. They're just folks with some weird ideas and (at worst) delusions of grandeur.
If we disrespect those who take the challenge, we underscore every negative stereotype about skeptics. At that point, the MDC stops being about inquiry and investigation, and becomes an excuse for us to point, laugh, and say "look at this clown." That doesn't do anyone any good--not us, not the "psychic," not the JREF, not Randi, and not society as a whole.
There's a reason why the JREF was able to keep 1,000 witnesses absolutely silent during the entire test. That reason is that, whatever Sonne might say afterward, we respect the process. A number of people worked very hard to design and construct an experiment to test the claim, and we owed it to them not to introduce any foreign elements (such as noise or flashing lights) into the equation.
The moment we start sneering and mocking, not only will we show that we no longer respect the process, but the process will no longer be worthy of respect. At that point it's nothing more than a sideshow, a stunt, a way for us to "expose" people for being on the "wrong side."
Perhaps congratulations are not in order, but respect certainly is*. Not for her sake, but for ours.
* Well, respect was in order, up until the claim of cheating.