I'm with the majority here.
It is not feasible to pardon someone from a crime of which they were convicted under the laws of the time - simply because they were a wonderful human being and contributed a lot to society.
Hitler loved dogs, but I don't imagine the RSPCA are looking to give him a posthumous mdal for it!
The crime was wrong, as more enlightened times have proved, but a crime it was, and if this man is pardoned, then every soldier shot for desertion should be shot, and every suffragette who went to prison should be pardoned, and so the whole illogical bandwaggon rolls on.
A statue in memory of Turing's contribution to the war effort would be appropriate, not pretending he was not a criminal which he patently was.
I entirely agree with Jack's sentiments, let's take our progression with regard to homoesexuality further forward, that would be a fitting tribute.