Another positive indicator is that we see great success for authors like Scott who did EarthCore. Giving away his book in audio form helped with sales. Also Cory Doctorow is, of course, giving away his novels and I think (but am not sure) that he's doing great with sales also. I'm sure there are more examples.
But on the other hand, O'Reilly has such a great reputation that it's not like they are unknown and desperate for ways to show people they exist.
Personally, I do agree that as electronic forms of documents get easier to handle and read, we'll need to have some reasonable way to manage selling and control of distribution.
I heard that the recording industry recently indicated that they are not in favor of watermarking to handle illegal mass distribution. At first I thought it was a generous and amazing comment. Then I realized it was probably not that they didn't want to impose a watermark on the content, but that they either didn't think it would be helpful in court, or even more likely that they want more control than that. They refuse to talk about the lesser controls of watermark when they are really after tight usage controls. Watermarks are about who the content goes to. DRM is about how, when, where, who and why you are using the content. DRM is a much much more controlling and restricting way of handling content, and if the recording industry can charge you every time you listen, or for every device you put it on, all the better in their eyes because it generates more revenue. Especially if they can sell limited access to content at prices similar to full ownership, because the public seems to naively accept it for now, and then the precedent will be set.
Okay, off my soapbox, but I do really hope that OReilly continues to be a big success, both with the great books and also with the generous attitude towards making the content available. In my mind, they are one of the heroes in the publishing industry.