Re: He may regret waiting
Trump may have been grateful to Assange for the help. But then there were allegations of links between Assange and Moscow. Specifically that Wikileaks got the DNC emails from Russian sources.
At which point he stopped being a useful ally, and became an embarrassment. At least if enough people believe those allegations - and there's credit to be had by dumping on him.
So the Trump camp have made a few noises about prosecuting him. But would they really bother? I presume it would need lots of prep work. Unless the Obama administration have already done most/all of it?
Then again is Assange's fear of US extradition a rational reason for his actions, convenient PR to cover his arse, or the product of genuine paranoia from a man who isn't all that mentally stable? Personally I suspect a bit of all 3...