On ZH someone posted an interesting idea. I doubt it is true, but it is reasonable and should be considered. Basically, how long would you want to stay locked up in an embassy? I wouldn't want to be in one at all.
Also, the investigation into the deep state is still ongoing, and they need witnesses against it who have more evidence to support the case. Who better than Assange? The theory proposed then, not mine, is this:
They bring him back to the USA, broker some sort of deal, he testifies against the deep state, and he's pardoned or something similar.
Trump is acting very strangely when it comes to this though, and yesterday he said he didn't know anything about Wiki Leaks. "That's not my thing." Uhm, hello? This is the same guy that mentioned Wiki Leaks 140+ times while campaigning.
I find it hard to believe that the deep state oligarchy, full of murderers and pedophiles, will actually be taken down. Who knows though. Stranger things have happened. No matter what happens we know Assange was part of the fight against them.
For that I salute him.