Only the most onerous local restrictions will be affected by the decision. It won't deter judges and others who believe the constitution should be defined by their idea of what serves the common good.
But this is nonetheless a huge, landmark victory. Many who respect the framers' intent, and who previously accepted the prevailing media and politcal interpretation of a 2nd amendment state militia "right", will be persuaded by Scalia's opinion for the majority. And though few will read it, many who previously dismissed the idea of an individual right will accept that there's a reasonable basis for the majority decision and reconsider. Especially those who saw poor confused Leslie Stahl's recent 60 minutes interview with Scalia.
As for a future liberal Supreme Court majority overturning this decision, I can't see it happening for many years. Most liberal legislators won't care as long as they still have ample power for restrictions. They love a political landscape that let's them propose gun restrictions and posture as crusaders for a better America. And as Lowell noted, the most liberal justices are in line to retire sooner than the conservative majority.
