Okay, let me tell this. I'm as far on the sliding scale of creative freedom as one can possibly be, which I suppose means I believe depictions of pedophilia that don't involve children should be allowed (unlike that UK law that just passed), and that is pretty much the only ground I'm willing to lose. I think any attempt by the government to tell people what they can and can't enjoy is ridiculous, based on the hateful notion that, if I am a good man and I don't like this, then it must be evil; or worse, that if I am a good man and I don't like this, then those who do are evil. It is pathetic.
I honestly see nothing wrong with this law.
It's stopping minors from buying violent videogames. It's not stopping their parents from buying it from them, if they think they're fit for it. It's stopping them from buying them behind their back. It's defending a parent's right to be selective about what their children play, as much as it's possible.
You say that it would set a precedent as games being seen as an special precedent that's somehow worse than other media. Fine, I buy that. It would also take away most of the air of the large majority of video game haters. Their main argument is 'think of the children'! And our only defence for that is 'hey, there's a system here that prevents children from playing games they shouldn't, never mind that it's run by the industry and it's not enforceable on a massive degree'. If this law passes, it will become 'They can't play it, no more than they can drink alcohol. It's against the law.'
Now, I don't want this law to pass, nor do I think it would be good for the medium as a whole if it did. But it's not the end-all doomsday you make it sound like in the article. If it's the first step of a slippery slope it'll be the least slippery of the slopes.
If gamers should gather around an ideal, it should be to press developers to make better games, more varied, appealing to a greater crowd. If every senator could look at GTAIV and see a variation of something they do on his free time, as they do when they look at a violent movie, the entire argument would lose its footing. Gamers should stop sitting atop their rock and shouting at the Eberts and Atkins of the world, turn around, and ask themselves why they ended up with that opinion.