1. Dead men can't stand trial. Unlike Sadam Hussien who was captured, tired, and then executed by a jury of his peers, Bin Laden can't go through the cathartic experience of going through a thorough trial.
2. Evidence collected from Bin Laden's house can't be used in court. If raiding a house without a warrant is illegal, then certainly flying covertly through another Nation, and breaking into, and killing the private residences breaks just about every Law that I can think of. So any actionable evidence that leads to another terrorist will just lead us to another Assassination.
3. Catch 22. The United States Government can't bring those fugitives before a court, so they will be forced to Assassinate them. This is exactly how we got into the Guantanamo Bay mess. By going outside the law, where we have become the very Terrorist we wish to catch. Is this how will we "bring to justice" other members of Al qaeda? Is Justice now just another Euphemism for being shot in the face? This is just another recruiting tool that will be used by used by Extremist groups against the US Government going forward.
Where do we go from here? Now that Bin Ladin is dead the cycle of killing has to stop. If we continue drone attacks, assassinating suspected Al Qaeda members, we will only continue the mistrust and hatred. However if the United States has to prove that is can apprehend people and give them a trial. But in order to do that do we really think the US will be grown up enough to do it? No. Just like when President Obama tried to close Guantanamo Bay, we can't trust the US to do the right thing. So perhaps the best thing is to compromise. Military Tribunals are not enough, but a full public trial on US soil won't work either. Perhaps their is a middle ground, where we could have a partially public trial, that will lead to proper trials in International courts, or on US territory.