You got it. A bad ruling would not affect the current legal status of the RKBA anywhere in the US. Agreed?
OTOH, there are potential upsides. SCOTUS could decide that the DC law is repugnant to the Constitution. Do you favor such a ruling? If not, what ruling do you favor?
It would be similar to the court's decision in Kelo. Do you believe that decision had no negative effect nationwide?
"OTOH, there are potential upsides. SCOTUS could decide that the DC law is repugnant to the Constitution."
The DC Circuit already ruled that. What's SCOTUS going to add? Tell me about these "upsides" of yours -- do you think SCOTUS will add machine guns and rocket launchers to home defense?
"If not, what ruling do you favor?"
Ooooh. I get to pick? I favor a ruling that awards me $10 million dollars.
Now that the fantasy part is out of the way, I think SCOTUS will rule that the DC Circuit went too far -- that even if the second amendment protected an individual right outside of a Militia, that right may be reasonably regulated by government under a rational basis review, not strict scrutiny.
Not agreed. A bad ruling would be: DC keeps its prohibitions, and thus Congress can extend them to the whole USA. No handguns period, and all long guns must be permanantly locked up, most certainly affects the current legal status of the RKBA everywhere in the US.