So the issue of indefinite detention is unresolved, though according to ScotusBlog, we have half a loaf:

The Fourth Circuit Court, in a splintered decision, upheld that authority under the 2001 Resolution, but did not rule on the government’s alternative claim that the President’s constitutional power as Commander-in-Chief supported the action. While the Supreme Court’s order Friday does not indicate how the Justices would have ruled had they gone ahead with their review, the order “vacated” the Circuit Court ruling, meaning that it no longer is a binding precedent on the issues it decided.

I’d rather see a ruling declaring the detention illegal, but the dismissal a bit better than the status quo.