I wrote a post in December 2010 on the question whether Sweden could extradite or deport Assange to the USA for illegal espionage or similar crimes after the UK has extradited him to Sweden for a criminal investigation on rape. My answer at that time was that unless the UK issues a new decision specifically on espionage he cannot be extradited/deported to the USA pursuant to the principle of speciality (section 12(1) of the Extradition for Criminal Cases Act).
I have found some additional support for this in legal doctrine. Cameron and et. al write the following in their book "International Criminal Law from a Swedish Perspective", Intersentia, 2011, p. 191:
It can be noted here, in connection with the EAW proceedings in 2010 concerning "Wikileaks" founder Julian Assange, that the principle of speciality means that Assange cannot be extradited or deported from Sweden, unless the UK grants its permission for this.I imagine that when the UK House of Lords in the near future delievers its decision on the matter, journalists will seek information on the Swedish law in this regard. I would recommend that you contact the authors of the abovementioned book.