Disagree, both on the practical outcome and the longer term legal implications. Practically speaking, this will result in considerably more guns being carried around New York. Whether that results in higher or lower crime, we'll just have to see, but it will certainly result in more gun related accidents. Legally, this decision has created a new rule regarding laws regulating firearms at the state level - that to be constitutional, a state must prove they are grounded in the "historical tradition" of gun control measures, which for Thomas essentially means at the time of the founding. Thomas' opinion also eliminates another step long used by circuit courts in evaluating gun control measures, namely to evaluate the dangers posed by firearms to the public. It's fair to say that the effect of this decision is that every single firearm restriction at the state level - age, background checks, etc. - is now presumptively unconstitutional. I'd imagine there will be widespread challenges to all of them, and under this rubric (and as applied by this Court) it's hard not to conclude that many will be successful. We'll just have to see if the Court decides to limit the application of this principal at all in future decisions (e.g., only apply it to CC licensing)
It's quite a radical expansion of 2A rights, even in the context of the already very 2A friendly regime ushered in by the Heller decision. And it's a curious infringement on the central tenet of federalism to give states latitude to determine their own laws, particularly in light of the coming abortion decision (which posits that abortion should be a question for the states).