There are, at the very least, some very dubious aspects surrounding the original claims: http://www.theguardian.com/media/2010/dec/17/julian-assange-...
I guess I am suggesting that due process, in this case, should be avoided - but only because this is clearly an exceptional situation, with some profound risks for Assange and other whistle-blowers.
The idea that any change to due process should be avoided because it 'sets precedent' I think is a misdirection. There appears to be not substantial reason for Swedish prosecutors to attend London and talk to Assange directly before making their (next) decision.
To be candid I don't really understand what his political ideals are - but I am informed enough to understand that it's more complicated than the way one might explain it to a 5yo.