I believe it went into effect in all of CA today (beginning of the year!) actually, although the date has gone back and forth some due to supply and converting existing operations. I'm pretty sure its been delayed before, not sure if it has been again or not though. I haven't had the pleasure of using it myself yet, but its been used for years now by the car manufacturers, and even longer than that by airlines. I have talked to a few folks that have used it as well as some knowledgeable paint store employees, and its really just a matter of getting used to a new system. Pressures required are different, as is the thickness of the application, the number of coats and drying time. Drying is a little more sensitive to temperature since no active hardener is used, but its not impossible to overcome even for the amateur painting at home. Paint guns with stainless internals are obviously better if you're going to be using it a ton, but older paint guns will work just fine if you flush them with acetone afterward to get rid of the water based stuff so the internals don't corrode or rust.
This is just plain ignorant. There was a huge resistance against the removal of LEAD from paint too. Seems like a no-brainer now don't you think? This isn't something new, paint has been evolving since Henry Ford. There's a reason all the earliest Fords were black, its because nothing else stuck to the car and lasted 
. Lacquer, acrylic enamel, candies and pearls, enamel without lead, clear coat systems, water based paints, its a long list. All have had their advantages and disadvantages, if you've ever sprayed lacquer you know its an incredibly different process than enamel. And I imagine if you've ever sucked up a lungful of lacquer or acrylic enamel you know that it can't possibly be good for you. 
Yes, the water based paints will take some time to get used to, and there may even be some color/shade matching issues for a little bit. I'm sure it'll lead to some botched up paint jobs, I'll probably be guilty of a few myself since I have a few to take care of in the near future. But it'll catch up, just like any technology. The paint manufacturers want to sell us paint, they'll figure out a way to get it done. Adapt and overcome. 
let me know how that waterborne junk works out for you ,it requires air dryers/blowers,because it takes forever to dry unlike solvent based materials,resulting in more trash. You can't just simply convert in a snap,you have to quit using all the etching primers,epoxy primers,2K primers and use something that you have no idea how well it works and if you can actually warranty all your paint/repair work for lifetime,like you're supposed to.Have all those shops you talked to switched completely over and use only waterborne primers,filler besides the paint? Sales people will sell you anything,and most of them never use products they sell.
Guess what happens to a spot that had a dent repaired with a skim coat of filler? filler is like a sponge and will absorb water,even if the moisture has been dried,it has already caused the corossion process. If you had a shop,would you like to keep redoing paint problems that were caused buy this new tree-hugger technology?say you blasted your car and government mandates, that you must used only waterborne primer,wouldn't you be be hesitant to use primer that contains more water than filler? what if all that primer cased rust a year down the road and now you have to rip the whole car apart and blast it again,and guess what, you can only use same waterborne junk primer
I simply refuse to test this technology on customer's cars and stand behind it without knowing how well it holds up.I'm sure you've see plenty of GM and Fords peeling back in late 80's and early 90's,
