Well, I see Haiku becomes more and more popular. I wonder on one thing - why would I be interested in next operating system if I have Windows 7 and Linux? What does it have that those systems haven't? I think authors of Haiku should find that and make sure that people that visit their site will read about that.
IMO BeOS was to operating systems what Opera is to browsers. Innovative, good ideas, efficient, ... but few people use it.
I remember demo-ing BeOS to a friend by opening a ton of videos at the same time. He replied that Windows did that as well, until he tried it and the system was trashing after the 3rd video. The "pauze" button in the copy/paste progress bar ... a revelation.