Despite what the media says, Assange has been completely forthright dealing with the police, and hasn't been "hiding". It's not like he got raided or anything to get arrested, he voluntarily went to the police station.
And yeah, in the US he hasn't broken any laws, which is what's causing the problems. The US was founded on the same principles that Assange is supporting, and the modern government doesn't like that.
Another good quote, "Palin demands that Assange be hunted down like Al Qaeda, so he should be fine for at least 10 years"