I imagine Assange's lawyers have done their homework and have established that from being on house arrest in the UK he could run for the Senate (contrary to what 1-2 commenters here have said).
There's probably few better elections to run in than the next one. It looks like the current Labor government will be decimated in the next election (in some ways history is repeating itself from the Hawke-Keating years, which is interesting).
Yet the population seems disillusioned with the opposition too. My biggest problem with the opposition is their pointless continued opposition to the NBN.
Anyway, the big potential headache for the Australian government here is Assange would go from being a citizen possibly being extradited to the Sweden (and potentially the US) to being a sitting Senator being extradited. While he wouldn't be a head of state and enjoy those protections, I'm not sure if there's any real precedent for extradition of someone in the government like this.
Australia should be standing up to the US over this however so it's a headache I would invite and welcome upon our government.
That all being said, I'm not sure I buy the theory that Assange's extradition to Sweden is to get his extradited to the US. I seem to remember reading something saying it was just as easy to extradite him from Britain so who knows.