And soon to be three if FSA ever gets their stuff out. It looks like Sampson and Sturmer-Archer are putting out complete drivetrains. I don't like the der. look on the Sampson, I dig the Sturmer-Archer though. Its good to see more competition, maybe it will drive prices down?
http://www.cyclingnews.com/tech/2007/shows/interbike07/?id=results/interbike071
http://www.cyclingnews.com/tech/2007/shows/interbike07/?id=results/interbike071