I remember when NY/NJ came out with law preventing employers asking your previous wages (they used to ask for W2!!!). People were saying, oh, employers just won't hire in NY/NJ anymore! Guess what, job market is still hot as the sun and salary range went up across all my job searches and I don't have to deal with bullshit recruiters trying to play with comps.
(And should we expect the specific regulations in NY/NJ (forbidding certain questions) and those in Colorado (requiring disclosure of information, and, requiring certain notifications of existing employees) to have the same effect?)