The 39-year-old Australian said he would continue to protest his innocence in the face of allegations that he sexually assaulted two women in Stockholm and vowed to continue releasing secret US documents through his website.
Following his release Thursday after nine days in a London prison since his arrest on a Swedish warrant on December 7th, Assange told the BBC the allegations against him were "a very successful smear campaign and a very wrong one."
He also told reporters that he expected the US, which has condemned the WikiLeaks cable releases, to bring spy charges against him.
Assange was freed after the High Court in London rejected an attempt by British lawyers acting for Sweden to keep him in jail while he fights the extradition attempt, a process that could take months.
As part of his bail conditions, he must live at friend's Georgian mansion near the rural town of Bungay in Suffolk, eastern England. He has also been electronically tagged, is subject to a curfew and must report to police daily.
Assange's release was the result of a nine-day battle by his lawyers. After denying him bail on December 7th, a judge granted it on Tuesday, but kept the Australian in custody while prosecuting lawyers appealed at the High Court.
Speaking to jubilant supporters on the steps of the court building after that appeal was denied on Thursday, Assange said, "I hope to continue my work and continue to protest my innocence in this matter and to reveal as we get it -- which we have not yet -- the evidence from these allegations."
WikiLeaks has caused embarrassment and anger in Washington by releasing hundreds of classified US diplomatic cables and his supporters have linked his detention to the massive leak.
As Assange arrived at Ellingham Hall, the 10-bedroomed Suffolk mansion that will be his home over the coming months, he said he expected the US to bring legal action against him.
"We have heard today from one of my US lawyers, yet to be confirmed, but a serious matter, that there may be a US indictment for espionage for me, coming from a secret US grand jury investigation," he said.
He expressed fears that the extradition proceedings to Sweden were "actually an attempt to get me into a jurisdiction which will then make it easier to extradite me to the US."
Swedish prosecutors have denied the case has anything to do with WikiLeaks.
Ellingham Hall, set in 240 hectares of parkland, belongs to Vaughan Smith, a former army officer and journalist who founded the Frontline Club, a media club in London which acts as WikiLeaks' British base.
"It is very nice to be free for Christmas and to smell the fresh air," Assange said as he arrived amid falling snow.
Assange said he had been held in solitary confinement for much of his time in London's Wandsworth Prison.
High Court Judge Duncan Ouseley granted the former computer hacker bail after rejecting the prosecution's argument that he was a flight risk.
"The court does not approach this case on the basis that this is a fugitive from justice who seeks to avoid interrogation and prosecution," he told the packed court as Assange looked on from the dock.
However, supporters had to pay £200,000 ($312,700) upfront as part of a £240,000 surety.
Assange's mother, Christine, told reporters outside court, "I'm very, very happy with the decision. I can't wait to see my son and to hold him close."
The latest US cables released by WikiLeaks on Friday showed the International Committee of the Red Cross provided US diplomats in 2005 with evidence of the systematic use of torture by Indian security forces in Kashmir.