Well, they didn't refit millions of TV's with the V-Chip once it was invented & approved
The V-Chip thing is just something that most people can understand & grasp, since everyone has a TV with it installed. It really is just another version of a program/script that blocks access if it's told to do so (just like the V-Chip)
Even if it's not a V-Chip, some sort of easy to manage pre-installed software on new computers that the user has the option of turning on & that software uses some sort of universal rating system (like the meta tags) would be perfect.