When in doubt, go with Occam's Razor. The most likely explanation is that this guy is what he appears to be. A very ardent pro-Norwegian cultural fanatic, who studied Islamic extremism enough to know they were winning, and who decided to turn their own tactics against them.
European culture is dying. It stands to reason that at some point, people this desperate will start appearing more and more. If his tactics look like Islamic extremists, well, guess what? They're the ones who have been working on asymmetric warfare for years. If you're one man looking to go out in a blaze of glory for insert-your-cause-here, then, that would be the place to read up on how it's done.
It would be lovely to think that our side is always chivalrous, tough and angelic, and the other guys are not just evil, but cleverly mastermindedly behind-every-dark-deed evil, but real life is more complicated than that.
“When in doubt, go with Occam’s Razor.... real life is more complicated than that.”
This may turn out to be a right wing loon attack exactly as you suggest.
My 12 point case above need more evidence to prove an Islamic connection, like did he go to Pakistan in the lasts years.
Guess the biggest cause of suspicion for me is how analogous the Norway attack is to the Oklahoma City bombing.
Reporter Jayna David argues persuasively that the OKC bombing was percieved as a right wing kook attack, but in fact had a connection to Islamic terror.
Makes me wonder if AQ is repeating a proven scenario. http://www.jaynadavis.com/highlights.html