Whoever may think that executing or just over-sentencing him would make him a martyr for the world, just think again: the MSM won't cover this or will cover it extremely biased (prolly stating Assange is Russian agent or smth - hell! prolly Wikileaks will be presented as a Russian fake news agency) and the normies will see it that way.

Point is, the US gov't has free hand to deal with him with impunity. Given who runs the CIA now, they'll probably keep him in Guantanamo for a bit before the trial.