I know the case to which you're referring, and the majority's reasoning was at odds with sanity. I believe Scalia summed it up quite nicely in his dissent.
What are your thoughts?
I'm not sure what you're specifically referring to, as there are a multitude of cases dealing with this topic. Everyone being held is entitled to some sort of process, but the question of what that process must entail is incredibly complex. There are cases that fall into almost every category.
Detainee is a US citizen captured in the US: Rumsfeld v. Padilla
Detainee is an alien captured in the US: Al Marri v. Pucciarelli
Detainee is a US citizen caputred outside the US: Hamdi v. Rumsfeld
Detainee is an alien captured outside the US: In re Guantanamo Bay Detainees Litigation
Beyond that 2X2 matrix, there are even more factors:
Detainee was captured outside the US in a combat zone: Hamdi v. Rumsfeld
Detainee was captured outside the US outside of a combat zone: Boumedine v. Bush
or
Detainee is being held on the battlefield: Al Maqualeh v. Gates
Detainee is being held off the battlefield: Boumedine v. Bush
My personal opinion is that it's incredibly difficult to look at these cases and conclude that you can draw a clear line about what rights each of these individuals deserve.
Does someone being held in the territorial US deserve more protections than an identical person being held at Guantanamo, and do both of those people deserve more protections than a third person being held at Bagram AFB?
As a practical matter, I don't know how I would rule on this. While it seems obvious that someone being held in a US prison should be treated differently than someone being held in Afghanistan, enforcing such a rule would just create a perverse incentive. The reason the US began using Guantanamo was because it was a place that the government thought would be under its control but would not offer the detainees the same rights as if they were held on US soil. Since Boumedine, the government has simply been shipping everyone they capture to Bagram. Now that a judge has indicated that that might be a no-go, who knows what will happen next?
Should someone captured on a battlefield in Afghanstan be treated differently than someone captured while plotting an attack in Pakistan or someone captured while traveling through the US?
I think the current approach on this is somewhat counterproductive - it offers additional protections to people captured here in the US while giving the fewest freedoms to those captured in Afghanistan. If we're trying to prevent terrorism, who is more dangerous - someone in a cave in Afghanistan or someone who is part of a sleeper cell driving to Chicago O'Hare?
In summary, I just don't know how I feel about this general approach. If you have a more specific question, I'll try to explain my thoughts on it as best as I can.