Not really. Britain's extradition agreement with the US is tougher than Sweden's. Britain can not extradite to the US where there's the possibility of a death sentence. The charges the US want to introduce would most likely come under the espionage act and he could face the death penalty.
Plus, public support for Assange is greater in the UK than in Sweden. Even if the request were successful, which is unlikely, it would take almost a decade, if not longer.
Oh, that's right, I forgot about the European Convention on Human Rights, I was too distracted by Sweden's consitent breaking of the rules by performing extraordinary renditions on Americas behalf.
But yeah, your probably right, there's no way Sweden will break the rules this time.
Extradition and rendition are two completely different things. If the CIA wants to rendition Assange, it'll just happen. It's an extrajudicial process more akin to kidnapping than anything else. If anything, the arrest warrant would just get in the way. It's hard to disappear people out of western European jails--easier to just grab him off the street, be it in London or Quito.
If the US wants Assange extradited, they would have to play by the rules. And the rules don't help at all if Assange is in Sweden.
Plus, public support for Assange is greater in the UK than in Sweden. Even if the request were successful, which is unlikely, it would take almost a decade, if not longer.