This is not a publicity stunt. The source code was leaked. How much of the source code from the entire project was released, I don't know. But from what WAS released, it is posing a problem. As many of you know, the cheat writers (OGC, myg0t, JAP <--these guys still around?) are probably already working on cheats for HL2, before its even out.
Yes this was posted over in the software forum, because, this is a software topic, not hardware. I know you'd like to inform everyone about this, but that's why Anandtech has multiple forums. 🙂