Edit: Or nothing at all has changed and the aim of the visit is purely "discovery".
I don't expect much will be different now, especially as there is no impending deadline like there was last year.
[1]: http://www.theguardian.com/media/2015/jul/23/julian-assange-...
So Sweden now does the interview so they can drop the case without losing too much face.
Assange goes free, and the US look for another way to snatch him or have him arrested by some allied state. (I am not even sure they would necessarily want to have him extradited - if he got convicted of rape in Sweden and went to prison for a couple of years[1], they might find that an acceptable outcome.)
[1] I have no clue what kind of prison time he would face. My gut feeling says 5-10 years, but my gut is not a lawyer and only has a very superficial knowledge of the Swedish criminal law.
The prison sentences for the crimes that may apply in his case seem as far as I can tell to range between six months and ten years (that is the harshest possible sentence for rape here in Sweden, and I can only imagine that it is given under very aggravating circumstances). Also bear in mind that almost every prisoner is released on parole after serving two thirds of their sentence - anything else is an exception.
Why would Sweden help the US when the UK wouldn't?
Edit: To clarify, Assange has been for years in the UK before he went into the embassy.
Now, grain-of-salt all that. I've read several things that a) say it's not exactly sovereign, but the political fallout of the U.K. entering the embassy could collapse the entire house of cards that is the Embassy system worldwide, b) states have been kidnapping and assassinating people on foreign soil for ages (see: United States, Russia, Israel, etc).
I'm sure being stuck in the Embassy is seen, at least a little, as being contained. But if he ever stepped foot outside, that'd be the end of that.
There would be a lot of other countries very pissed at us for smashing it to bits in such a public way.
Second: do you have evidence that the US sought Assange's extradition prior to him taking up residence in the embassy? What would he have been extradited for? He's not a US citizen and has no duty of care for confidential information from the US that was never vouchsafed with him to begin with.
Not weeks, years. He left Sweden in 27 September 2010, and it wasn't until 14 June 2012 that he had exhausted his rights of appeal in the UK (short of any appeal to the European Court of Human Rights in Strasbourg). He was on bail for pretty much the entire period (he spend nine days in police custody prior to being granted bail, but I don't believe he was ever in custody after that).
(Disclaimer: I don't know nothing, I just think I heard.)
If he were to be extradited to Sweden from the UK, and if the US wants him extradited from Sweden, the UK would have to give their permission to do so. Sweden would simply be an extra complication and wouldn't help any extradition claim the US might have.
http://jtl.columbia.edu/wp-content/uploads/sites/4/2015/04/F...
Which place he gets sent comes down to the decision of someone, likely the Home Secretary, but my memory of this is fuzzy and it could be down to the judiciary.
All that to say, I doubt they'd secretly kidnap Assange to put him on trial in the US for... publishing documents given to him by other leakers? It's not exactly a clear cut case, I don't think. It'd be more politically agreeable to kidnap some terrorist for that kind of thing.
It's totally possible that there are legitimate reasons for that (if you already have enough evidence to convict, there would be no reason to 'interview' someone except in an arrest-friendly setting), but it's still a worthwhile distinction. This isn't someone calling up the police and going "I'll talk to you, but only if you agree to meet me at Starbucks." It's someone leveraging international law to leave the police with only one option.
Just a theory.
> Assange did threaten to release a bunch of documents
> about Clinton