This means that ALL gun control laws may now be considered unconstitutional.
Doubtful that will be the result. From the NYT article on the decision:
..."But the court held that the individual right to possess a gun “for traditionally lawful purposes, such as self-defense within the home” is not unlimited. “It is not a right to keep and carry any weapon whatsoever in any manner whatsoever and for whatever purpose,” Justice Scalia wrote."
“Extinction is the rule. Survival is the exception.” -- Carl Sagan