The question of the likelihood of US officials facing prosecution in light of the US Senate's recent CIA torture report is a bit narrow. It does not include Bush, Cheney or Rumsfeld who actually pushed the practices from the very top of the administration. I doubt there will be any prosecutions; only CIA whistle-blowers get prosecuted.
The US Senate Report is pretty much along lines one would expect. It further undermines US moral authority, its disregard for US law and international law, including the UN Convention against Torture. There will be lots of denials and hand-wringing but many of those practices are still going on.
The Bush administration placed CIA interrogators under severe pressure in the wake of 9-11 to find a link between Saddam Hussein and Al Qaeda, to no avail of course as there was no link. Unsurprisingly, Bush has come out to defend the CIA, which seems like a self-justification for his, Secretary of Defence Rumsfeld's and Vice President Cheney's roles in the torture policy.
But torture has been a fairly routine practice of successive US administrations -during the Philippine insurrection of 1900-1908, for example, when waterboarding was used.
The Obama administration wanted the report, including the summary, classified, (i.e. censored). And despite halting torture by Americans, Obama has done nothing about the torture carried out by US allies in Pakistan, Egypt, Jordan, Bangladesh, Kenya and other nations under American supervision. Hence, torture and the US remain inextricably linked. Blacksites, and secret prisons remain and are staffed by non-Americans, who are doing exactly what the US Senate Report highlights.
Guantanamo and Bagram remain open and holding a number of 'enemy combatants' without charge. The mere fact that they are outside of US constitutional reach tells anyone who cares to stop and think that they must be torture chambers.
In regard to Bangladesh and Kenya there seems evidence, or at least strong claims, that British security services were either complicit or involved. There are claims by a parliamentary committee into the death of Lee Rigby, to the effect that one of the killers was tortured by a unit in Kenya that collaborates with, and has been funded and trained by, the British secret services.
There will be lots of declarations of America having lost its way but the fact is that the practices are still going on either by Americans or supervised by Americans in allied states. The fact that torture does not even yield accurate or useful information is, to my mind, beside the point; it's logic suggests that if torture did yield information, it would be justified.
Civilised states do not torture people.