Lots of people have been openly wondering about this, including me.
If this video is to be believed then there is a list of reasons as long as your arm that would make any rational person in Assange's situation stay well out of Sweden's reach.
Just as one example, you could just stop at the fact that Karl Rove is advising the Swedish government - yes that Karl Rove, who's attitude to an underling who wouldn't follow the party line was to say "We will fuck him. Do you hear me? We will fuck him. We will ruin him. Like no one has ever fucked him!". The same Karl Rove who appeared to be instrumental in punishing Senator Jo Wilson in nakedly political revenge, for him casting doubt on the case for Iraq's possession of WMDs, by outing his wife, Valerie Plame. Valerie Plame who was at the centre of a CIA operation monitoring Iran's WMD programmes; with part of the fall out being that the CIA estimated it had set them back 10 years in their monitoring of Iran's putative ambitions.