I don't find the fact that Failoverflow discovered the key to be a problem, in fact it's pretty impressive. The problem is that they gave the key to another hacker "Geohot" who decided to publish it on his blog. He claims that he is against piracy and that Sony's removal of the "other os" functionality was the first blow. It's interesting that his use of the feature as an avenue to crack the system and his publication of the methods he used was the catalyst for its removal. Now, Geohot has opened the door for the world to create custom firmware for the PS3 and run pirated games. There's no doubt that he knew the repercussions of posting the key to the public. Sony is now suing him and I fully support Sony.
If Geohot truly doesn't support piracy, then the action of publishing the key in his public blog is simply irresponsible. Sure, he isn't directly pirating games, but he's making it possible for others to do so. He claims that he specifically designed the hack so that piracy can't be done in the way it has in the past, but he of all people should know that hackers are constantly adapting to new restrictions. He may find a way to argue in court, but he is clearly in the wrong here.
I'm interested to see how this turns out.