I have no information. But, if it was Muslims, be sure to read what expatriate journalist Bruce Bawer has to say. He lives in Norway and, though otherwise quite liberal, has been on the case of the Islamization of Europe for some time.
Update: Rumors are trending away from it being the world of Muslims. I'll repeat my recommendation to see what Bruce Bawer says, though. He speaks the language and writes for the Norwegian newspapers sometimes. So he's a good English portal into Scandinavian doings.
Update the second: 80 dead. This is beyond horrible. Sympathies to the victims & families. And a grudging, muttered "sorry" to Norway's Islamic population: looks like a right-wing extremist is shaping up to be responsible for this one. Though I ought to take my own advice and go with the 48 hour rule.