This has happened a while ago, but the video along with Tim's take on the event is available now. I don't want to add too much to what you can watch and read there, but the scoop of the issue is this.
Eben Moglen criticizes, quite harshly, Tim O'Reilly for focusing so much for so long on who does what with Free Software and who makes how much money - basically the practicalities, the market trends and hype - while ignoring what really matters, the actual problems that the Free Software movement is facing, the "public policy", the freedom. The way he described facebook was one of the best "got it" moments for me with regards to the picture he wanted to portray. Who cares about what facebook and whatever other "Web 2.0" company is doing at the moment. They're just doing their business and we don't need to have a whole freaking conference talking about how they're doing their business, making money and how cool all this is. That's how I got it.