Arizona's reaction is HB2291p
Similar to other states AZ is looking to pass a bill that tells the federal Government to back off, these are State issues to settle. Notice this does not seem to conflict with the NFA and and other Federal Firearms laws currently in place.
At the same time last night I got an email from Mr. Barber of the AZ Congress who has himself submitted a new AZ. House bill that establishes a state AWB, Mag limits, Background checks for private sales, the entire Obama enchilada.