Personally I think the reason the press is out to get Assange is that he's made them look stupid - a lone computer hacker from the middle of nowhere gets a better scoop than they have managed in decades? Lots of noses put out of joint I suspect.
As for the US prosecuting Assange, I really don't see what they can do him for. They **might** be able to get him as an accessory to Bradley Manning's alleged crimes if Assange is shown to have encouraged him, but the rest of the political posturing is just that - he's got an almost watertight first amendment defence against the various espionage and treason accusations (not to mention the fact that many of the charges don't apply as he isn't a US citizen).
So far as Sweden goes, Swedish and EU law is clear that he can't be extradited to the US without the permission of the UK. Additionally, any extradition request has the protection of both the UK and Swedish courts. Were he to somehow manage to stay in the UK, he would only have the protection of the UK courts - and we haven't exactly demonstrated a good record of declining to hand over people suspected on dodgy charges in the US...