The idea that a "license" is required to exercise a clearly defined Constitutional right is the most ridiculous concept I have ever heard. Should the Govt. require you to purchase a license from them to exercise free speech or to attend the church of your choice?
An oft stated sentiment.
And there's no CCW until you have a license, or until a State passes a separate law saying you don't need one.
States have rights, also, and can clearly enact laws pertaining to firearms.
What isn't clearly defined, are the amount of restrictions that can be placed on the citizenry. Scalia said in a recent interview that he'll have to "see what happens" with respect to how he'd come down on the matter should it go before the Court.
What we'd better worry about is who's going to be appointing Justices for the next four years, since the rulings by some are not in doubt.