Right now, according to the Pentagon, there are about 549 detainees at the Guantanamo Bay detention centre, from around 40 countries.
Hundreds of detainees are still imprisoned at Guantanamo Bay
That's down from the peak of about 680 in the middle of last year.
But the controversy surrounding the prison has hardly diminished at all.
Indeed, the Bush administration's detention policies have been perhaps the most consistently controversial aspect of its "global war on terrorism".
It's an issue that just won't go away. The critics allege that the prisoners at Guantanamo Bay are being denied basic human rights and justice by being held for so long without trial.
And Guantanamo Bay became sucked into the wider row over prisoner abuse.
Pentagon officials acknowledge that more arduous interrogation techniques than normal were first authorised and then revoked.
But they insist there has been no torture authorised at Guantanamo.
And, despite numerous allegations from released detainees, they insist the prisoners are treated humanely.
When there has been some mistreatment, they say, the guards concerned have been punished.
Pentagon officials still contend that the laws of war entitle them to hold "enemy combatants" without charges or trial for the duration of hostilities
But now there is an almost bewildering array of reviews and court challenges swirling around Guantanamo and its prisoners.
There has been a new focus following the US Supreme Court ruling in June that the detainees should have access to the US court system to challenge their imprisonment.
Guantanamo's inmates are at the heart of a legal wrangle
Since Guantanamo Bay was established as a prison, more than 200 prisoners have been released or, in the Pentagon's words, "transferred to the control of other governments".
The releases total 146 so far, over more than a year and a half, the number of transfers 56.
The largest batch of releases occurred last month. Eleven prisoners were sent back to Afghanistan for release, six to Pakistan, while 29 were handed over the Pakistani government.
But also last month 10 more detainees from Afghanistan were added to the Guantanamo prison roll.
Among the other transfers to other governments have been five sent to Morocco, four to France, seven to Russia, four to Saudi Arabia, one to Spain, one to Sweden, and five to Britain - although they were then released quickly.
Campaigners insist it's all taking too long, although the Pentagon says the releases are not without risk.
It says it has evidence that at least seven former detainees have returned to fighting US-led forces.
None of this has satisfied the critics, and indeed the Pentagon was clearly caught off guard by the Supreme Court ruling in June.
Its response was to set up what it calls Combatant Status Review Tribunals. Involving panels of three military officers, they are to review whether those being held were correctly labelled as enemy combatants.
So far, more than 180 tribunals have been held, and decisions reached in 96 cases. All but one have been confirmed as enemy combatants, and that prisoner has now been released back to Pakistan.
The Pentagon believes these tribunals satisfy the Supreme Court demand for "due process".
Campaigners for the detainees insist they don't. For one thing, they argue, the detainees don't have access for lawyers for this.
So the court challenges for more than 60 detainees go on. And so do the negotiations to get more access for lawyers to the detainees.
But that's by no means the end of the procedures involving the detainees. In some ways they get even more controversial.
Before the Supreme Court ruling the US Defence Secretary, Donald Rumsfeld, announced in February plans for another set of annual reviews for all the detainees, to consider whether they still represented a threat to US security.
Part of the tribunal proceedings were open to journalists
They've been held up by the Combatant Status Review Tribunals.
But these panels - again in front of three military officers, and without lawyers - appeared to have been announced in part to try to stem some of the complaints about US detention policy at Guantanamo Bay.
However, they're also a tacit acknowledgment that some of the prisoners could be held without trial for years.
And finally, there are the military commissions - the original tribunals - for those detainees the Pentagon believes committed war crimes.
These will be full-scale trials. Pre-trial hearings have already been held.
But, so far, only four detainees have actually been charged with offences.
The Pentagon insists the commissions will be fair. Many, including the British government, are not convinced.
To add to the concerns of some critics, Pentagon officials acknowledge that even if these detainees or others who face charges are found not guilty by military tribunal, they could be kept prisoner if they're still considered a security threat.
If found guilty they could also be held beyond any sentence laid down by the tribunal.
The officials argue that there are two processes under way.
Detainees are being held because they're suspected of being enemy combatants in an ongoing war.
Separately, some are being put before tribunals accused of specific war crimes or other offences.
But the officials say it would not be common sense to release detainees after the tribunals if the "war on terrorism" were still under way and it was thought they might launch new attacks on US interests.
The officials add that anyone convicted of war crimes would still have to serve out their sentences, even if the other detainees were released because the war was deemed to be over.
All this looks like further evidence of how difficult the issue of detainees is.