All the juicy info is over at http://gamepolitics.com/2011/06/27/esrb039s-reaction-statement-scotus-decision. I like the ESRB's take: empowering parents is the best way to go. I think that is a position that Magisterial-minded Catholics could agree with.
We've had plenty of discussions about video game violence and the like on this blog in the past. Now might be a good time to revisit them; in any case, a good Catholic approach to the issue can be found here:
Don't let the mask of "prudence" and "protecting children" lead you into rejecting Christ.