There was an initial warrant which was dismissed. He is now wanted for questioning to determine whether further warrants may be applicable. Sweden requires an interview before issuing a warrant.
He is being given asylum because the US has a rather poor record of extraordinary rendition and human rights in general. Of course, rendition is no longer necessary since he just needs to be declared a terrorist (no proof necessary) and he may be detained incommunicado forever without any charges whatsoever as soon as his feet hit US soil.
It's good to live in the land of the free, isn't it?