This bill (for those of us following it since it's inception) has really been watered down. The first version wasn't a "noise" bill at all. It was a smog bill. It called for every motorcycle on the road in California to pass an annual smog test (just like cars.) When that didn't pass out of committee it was rewritten as a noise law (basically saying no non-stock pipes) also for every motorcycle on the road. That didn't get out of committee either. So the bill was amended to just 2011 bikes and later, then 2012 and later, and finally 2013 and later. And that's the one on the Governor's desk right now.
You'll hear the misinformed always bagging on California but we really are one of the less restrictive states regarding motorcycles. There is no annual inspection here like many states in the East, no smog checks, even some parts of metro-Arizona have those, and no egregious pre-registration inspections on custom built bikes. (It's just a simple numbers check.)
And we can legally lane split!
If this was the sort of deal that people got to vote on we'd lose big as the average cager would vote to remove us from the roads altogether if that was possible. One of the most boneheaded things we American citizens do is when the rights of a minority are threatened and it doesn't affect us personally we just don't care. You don't have to be much of a genius to see how that winds up in the end . . .