It's D-Day today...

I'm still completely confused on what the pineapple this law is doing. From what I understand it basically just prevents minors from buying M-Rated games, to me, this seems like common sense. Am I missing something?

Not quite. Pretty much, the state of California force retailers to hide games that the state deems violent. The law's definition of "violent" is vague however, so the fear is that the law's loose definition will hit anything that has some sort of violent content, e.g. SSBB. All of this because of "panic" over violent video games causes people to go kill or something.

Also, there's already ratings in place, as well as retailers already carding people who tries to buy M-rated games. Why have the government control what's already self-regulated and working?

Here, I'll give you a linky that can help you: http://www.theeca.com/schwarzeneggervema