Trump should do a lot of things but he'd never do this. I believe he said he'd never pardon him -- or maybe that was Chelsea Manning. Can he even pardon non-us citizens?
I doubt Trump was referring to Manning seeing as her sentence was already commuted by Obama in Jan 2017
The extradition process will likely be long and drawn out, but unless someone significant steps in with serious political power they'll probably ship him off to the US eventually. The UK is too pally-pally with the US for them not to. Maybe Assange will get bail and go walk about, though (but I doubt it).
IIRC Assange already missed a bail hearing in the UK, regardless of that fact, the UK will
never give him bail because he is the definition of a flight risk!
The case against Assange is flimsy as fuck, the Obama administration had all of this same information and they decided NOT to prosecute Assange (they worried they couldn't make such a flimsy case stick). The hard liners currently in charge of the DOJ have a different opinion.
The fact that the statute of limitations was 4 days from expiring for the indicted crime is not coincidental. This was/is their last shot at getting Assange for the 2010 "incident". As I mentioned before a superseding indictment adding crimes is always a possibility but that would require new evidence to be presented to back up that indictment.
There is another level to this as yet widely unreported. According to UK law when a person is extradited ALL charges must be present at the time of extradition, this could include sealed indictments (which we would not be privy too). Basically what the UK law means is that you can't extradite someone for one crime and then PILE on a whole lot of other shit once you get them home.
Its funny how many people in the forum have no idea how complicated this case is going to be, it is by far anything but a slam dunk for the US DOJ.