That case is already in the works in DC. http://voices.washingtonpost.com/local-opinions/2009/09/gun_owners_next_victory_in_dc.html
This case is to “incorporate” the amendment to the states (thus binding them to the same obligations as the Fed Gov), through the 14th Amendment.
Also, just remembered, that once incorporated, there are several “by dicta” rulings that the governments cannot restrict open carry without a permit, so he’ll be allowed to carry, just not concealed.