in the challenge to the D.C. gun ban, holding that citizens can't challenge the ban unless they're being prosecuted for violating it, or at least have shown some serious threat of imminent prosecution. Haven't closely read the whole decision yet, but that's the gist.
Neither the majority nor the dissent express a firm view on the Second Amendment issue. Both opinions acknowledge that the Second Amendment challenge raises an arguable constitutional question, but they don't explain their views on that question (which makes sense given that the debate is about the procedural issue).
Thanks to Matt Rustler for the news.