Well if you know Royksopp then it is similar to that kinda thing. It's NOT drum'n'bass as Don suggested. (although I don't know what style the DJs will be playing).
According to the Registratur flyer he will be singing live. So I don't know exactly what that means.
For a taster go to amazon.com - search "erlend oye", click on "unrest" the album and you can hear clips.
Also go to hmv.co.uk - search "oye" click "unrest" the album and again you can hear clips. I don't have any of his stuff with me, otherwise I would host some songs for you.
Alternatively go into a music store and ask to listen? Maybe they have listening posts?
As for his website - it opens a Flash site, you can hear songs by clicking on the countries and selecting "listen to a song", which then plays a RealMedia clip.
Also go to
http://www.k7.com where you can listen to clips from his new single, and his mix CD for !K7 - DJ Kicks. (all in RealMedia format)
Having not been to Registratur before I don't know what the music richtung there is like, but I've heard good things. I do know Erlend Oye and his stuff is certainly not hard.
I just hope with some of these posts I encourage some people to come listen to some good music with me!