The distinction between terrorism and crime is that terrorists seek a political end. Breivik wants to establish a new political regime and his atrocity is furthering that goal. I suspect he's modeling his plan on the Beer Hall Putsch. Hitler's coup failed with deaths on both sides but he gained a powerful platform for his propaganda from it. For high treason and 22 deaths he was sentenced to five years in a comfortable prison and only served eight months of that. The newspapers printed his speeches during the trial. He wrote his manifesto in prison. He kept leadership of his movement by mail. Once he was released he re-entered politics with an even more powerful base.
Breivik's already written his manifesto. He's laid out a structure for his hoped-for political organization. He only faces a maximum of 21 years in a comfy prison for his acts. Even if he doesn't get a pardon he'll emerge at 53 years old ready to continue his struggle. I saw a photo of him in the police car. That was the smug expression of a man whose plan is going just as he wants it to. He may have the more modest goal of just trying to get people to read the manifesto. In that case he's succeeded completely. The professional photos (for which he'd prepared with tanning and manicures) indicate he was preparing for world-wide publicity to descend on him.
I'm assuming he's more interested in seizing domestic power than waging the war he talks about by his choice of targets. There's plenty of Muslims in Norway to provide targets for a massacre. Attacking the Labour Party was an attempt to weaken the current political establishment.
Then again, he may have just been looking for the softest target. Liberal political activists are the least likely group to effectively resist an attack. A Muslim group would likely have started shooting back. Even a soccer camp might have taken him down with a mass tackle while reloading. I'd like to think some of the teens on Utoya had the courage to rush him--but with no experience in physical teamwork they would have died alone along with any witnesses to their heroism.
Massacring Muslims would also have inspired a Muslim inmate to shank him in prison. Picking victims without an ethic of revenge lets him wait safely to re-emerge.
Writing the manifesto in English indicates he may intend his new movement to be pan-European rather than just Norwegian. The meeting founding his "organization" was with citizens of other countries. I expect he's hoping for some of the people downloading his document to start founding their own chapters. Hence the need to award himself rank and decorations in advance.
As an aside--fundamentalist Christians, and other devout but less dogmatic Christians, punctuate their writings with Bible verses and regularly connect their assertions to biblical authority, preferably direct quotes from Jesus Christ. The manifesto is notably lacking in that. If Breivik is a Christian he's likely just a squirrel. I suspect he just likes the Templars and Crusaders because they fought Muslims, not because they had any connection to Jesus.
Breivik's ideology clearly wants to establish an all-controlling state. His main objection to Islam seems to be that it may get there first. His focus is on defeating "traitors" so he can establish his state and wage war against Muslims.
Now that's Breivik's in his nice safe jail cell what's his next step? I think he's counting on his manifesto and courtroom speeches to create a fascist equivalent of Sudden Jihad Syndrome. Individuals would pick up his cause and either launch terrorist attacks or start organizing cells of his "Templars." If someone strong personal charisma joins the cause it could start growing at a dangerous rate (as Godwin's is still suspended I'll point out that Hitler's personal magnetism was a powerful element in the Nazi rise to power). Fortunately Breivik is utterly lacking in that as proven by his inability to recruit even one trustworthy accomplice.
Stopping Sudden Fascist Syndrome attacks will be extremely difficult. Like Breivik, someone exercising perfect operational security is hard to detect. This has to be fought at the memetic level, declaring members of "Knights Templar PCCTS" out of the bounds of civilized discourse. This has to be done on the "anti-jihad" side of the debate since the left side is already trying to proclaim all their ideas out of bounds anyway. People with credibility in arguing for the defense of Western culture will have to confront PCCTSers. Stopping Muslim efforts to carve out Sharia enclaves in European cities will also be needed. If the real governments can't win that fight the losers will look for another route--and Breivik will be there waiting for them. The more marginalized the ideology is the less likely someone seeking a cause will adopt it. Stopping groups from organizing will also reduce the number of individuals launching solo attacks.
If we can step on his memes hard enough Breivik will emerge from prison in 2033 or so as alone as when he started his attack.