It sounds like the people around him are confident it's a done deal, with his time in Belmarsh acting as 'time served' for a more minor breach of thae espionage act.

But I'd still be worried the US pulls some shit as:

Assange is scheduled to appear in a federal court in the Northern Mariana Islands, a US commonwealth in the western Pacific, where he is expected to plead guilty to one charge under the Espionage Act of conspiring to unlawfully obtain and disseminate classified national defence information. The extradition request is expected to be dropped and Assange won’t face any other charges.

The hearing is taking place in the Northern Mariana Islands because of Assange’s opposition to travelling to the US mainland and the court’s proximity to Australia.

Prosecutors have agreed to a sentence of five years, but have said the time already served in a British prison will count towards this. This means that he will probably walk free after the sentencing.

The guilty plea must still be approved by a judge, but if it is, he is expected to return to Australia after the sentencing.

What if the judge says 'no' and gives him a much harsher sentence to be detained by the US?

What if they just straight up black bag him?

On a tiny Island with only one or two witnesses instead of a busy city with a (nominally) free and interested press.

I hope this is the end of the ordeal for him, I truly do, but I don't think I'd ever believe it until I was safely in a country I was sure would never extradite or collaborate with the US. Although right now it's clear he doesn't have much of a choice.