If he has, and the US could provide a good case, then he would likely be extradited from pretty much anywhere. Why does it need to be Sweden? If, as you state, he could easily be extradited to the US from here, then why do the three 'offences' need to be linked?
Why should they guarantee that when he might have committed a crime in the US?
We know their names i think it would be a strange system which allowed us to know who the accusers are but not any of their corroborating evidence at all. And when i say us, i dont mean me and you. I mean a uk court, with uk judges.
I have no idea of the protocols of Swedish justice but how do we know they have no/little evidence of a case? I doubt it would be acceptable to broadcast the evidence as it would prejudice any potential trial. They've put a legal warrant together that Assange has done absolutely to try and evade, legging it to the Ecuadorian Embassy and claiming political assylum is the act of a desperate, not an innocent man, in my eyes. But even then he can go to Sweden and stand trial, if he's innocent there won't be enough evidence to convict him in Sweden.