S&W are now selling a version of the .22 AR-15 patterned M&P15-22 that is compliant with Connecticut, Massachusetts, Maryland, New Jersey and New York law.
It has been made compliant by fixing the stock so it cannot be adjusted and supplying a 10 round magazine. The MSRP is still $499.
The pistol grip and removable magazine prevent it from being California compliant. .22 Rifles are exempt from California Assault Weapon laws.