Assange and WikiLeaks said on Twitter that some enemy of the site was using the rape accusations as "dirty tricks." According to The New York Times, Assange claims that even though the charges were dropped, damage has already been done because enemies of the site can use the rumors in a war of public opinion and perception.
WikiLeaks drew fire from the Pengaton and other governmental organizations for releasing more than 70,000 secret military documents about NATO's Afghan War, and it's clear from its Twitter updates that WikiLeaks believes those organizations are trying to prevent the site from releasing 15,000 more documents that Assange calls even "more explosive."
Assange was reluctant to directly name the Pentagon or any other specific government or intelligence organization as the instigator of the rape charges. He has simply said, "We can have some suspicions about who would benefit, but without direct evidence I would not be willing to make a direct allegation."
Assange was in Sweden to arrange for some of WikiLeaks' operations to be hosted there. The country is known as a safe haven for radical freedom-of-information types like Assange and the founders of The Pirate Bay. In fact, The Pirate Bay and its loosely associated political party The Pirate Party will host some of WikiLeaks' servers moving forward.