Tim O'Reilly gave a presentation you can listen to here.
I think he has some very valid points on where the open source movement is & needs to be heading. I am a fan of open source philosophy, but do think there is, at this point in technology's development, still a need for some proprietary software. I haven't fully developed my stance on this statement, and it is late now&, so I will not attempt to hammer it out now.
All in all, I agree with Tim that Amazon has some amazing technology behind their site and enjoyed the comparison to Barnes & Noble's website, as it illustrates his position well.