It will be one of those narrow-focused rulings we get from the Supremes.
How is that different than what the DC Circuit ruled? In other words, how is this ruling different than if the U.S.Supreme Court declined to hear the case and let stand the DC Circuit decision?
That's not under consideration. The only thing under consideration is whether the right is an individual one, and if 3 specific sections of the DC code violate it, if there is one. IIRC, none of the DC code sections concern either felons or the mentally ill.
The way they, the Supreme Court itself, worded the Question, it almost assumed there is an individual right. But that might be reading a bit too much into the wording... and maybe not. Time will tell, and not much of it at that.
07-290 DISTRICT OF COLUMBIA, ET AL. V. HELLER, DICK A. The petition for a writ of certiorari is granted limited to the following question: Whether the following provisions, D.C. Code §§ 7-2502.02(a)(4), 22-4504(a), and 7-2507.02, violate the Second Amendment rights of individuals who are not affiliated with any state-regulated militia, but who wish to keep handguns and other firearms for private use in their homes?
7-2502.02 (a)(4) only allows possession of handguns registered in DC prior to 1976) 7-2507.02 requires guns to be disassembled and unloaded, even in ones own home), and 22-4504 prohibits carrying a pistol without a license. All apply to normal law abiding citizens.