We don't know much yet about Breivik or his motivations. However, he does appear to have been part of the political right. It is already the case that some on the left regard white males as the "cosmic enemy" - as the group responsible for creating privilege and hate and holding back progress toward equality and justice. Breivik's crime is going to encourage this negative way of identifying white males.
I don't know what will come out about Breivik over the next few days. However, there are a few things to be said about the information to hand.
First, the information so far does not point to Breivik being a fundamentalist Christian, as a few newspapers are reporting. It's true that he was baptised into a Protestant church and that he wanted the church to go back to basics. However, there is a picture of him in masonic uniform and he listed masonry as an interest on his Facebook page. He wrote too that he wanted to defend the "cultural aspects of Christianity" rather than Christianity itself. Finally, he listed his favourite books on his Facebook page and these are nearly all key works of non-Christian (or non-orthodox Christian) liberal philosophers such as Hobbes, Mill, Kant and Adam Smith.
The first two books he mentions are by William James and Richard Rorty. Both of these men deny the idea that there is an objective good that we should seek to live by. According to James, a belief was true if it had good consequences for the believer:
A belief was not a mental entity which somehow mysteriously corresponded to an external reality if the belief were true. Beliefs were ways of acting with reference to a precarious environment, and to say they were true was to say they guided us satisfactorily in this environment. In this sense the pragmatic theory of truth applied Darwinian ideas in philosophy; it made survival the test of intellectual as well as biological fitness.Richard Rorty was a self-described "bourgeois liberal" who denied that there was an intrinsic structure to reality. Instead, what was "objective" was what a group of people decided amongst themselves to be true:
Maybe someday the idea of human beings answering to an independent authority called How Things Are in Themselves will be obsolete. In a thoroughly de-Platonized, fully Protagorean culture the only answerability humans would recognise would be to one another. It would never occur to them that “the objective” could mean more than “the agreed-upon upshot of argument.” In such a culture we would have as little use for the idea of the intrinsic structure of reality as for that of the will of God. We would view both as unfortunate and obsolete social constructions.
These ideas are a long way from orthodox Christianity (Rorty even describes the will of God as an "unfortunate and obsolete social construction"). They are not what you would expect a fundamentalist Christian to approve of or to recommend.
As for his politics, Breivik seems to be a radicalised right-liberal. What I mean by this is that he identified with classical liberal thinkers like John Stuart Mill (whom he quoted in his one twitter message), but he also saw the growth of Islam in Europe as a threat to such values. So he was against open borders and multiculturalism. He blamed the Frankfurt School and cultural Marxism for what had gone wrong in Europe.
But there has to be something else. None of this really explains why Breivik would commit such an act. Even if I'm correct and Breivik was a "cultural Christian" rather than a more orthodox one and a "cultural conservative" (i.e. a right-liberal who wants to defend a Western liberal culture from Islam), that still doesn't supply the motivation to commit such an atrocity.
You would have to think that certain traits of character or personality will emerge over the next few days that might help to fill in the gaps.