This is covered in the article. Sweden has now (as of March) said they would be willing to interview in London.
http://www.aklagare.se/In-English/Media/News-in-English1/The...
http://www.thelocal.se/20150618/swedish-prosecutor-cancels-a...
http://www.aklagare.se/In-English/Media/News-in-English1/The...
http://www.thelocal.se/20150618/swedish-prosecutor-cancels-a...