First off, I don't believe this is a California CARB plot. Yes, I'm a Californian, but look at this from a manufacturers perspective, i.e., a separate model for Europe, maybe a separate model for Asia, a 49 state model, and a separate model for California.
I will accept that California has better air than in the '60's (if that's what they claim, I have no proof to the contrary). But, you've got to acknowlege that more people riding and driving worldwide, puts more of a strain on our extremely important air supply.
The rest of the world is slowly waking up (even China will, someday) to the critical need for a higher quality of air, water, etc.
It makes sense to produce a single model that protects the environment everywhere and not just where laws have put strict controls on emissions. Although I am not an advocate of more government to protect us from ourselves, I am an advocate of manufacturers taking a more active role in maintaining or improving the quality of the world's environment. After all, what's (where's) the alternative?