Current technology book market trends

Kevin Bedell quotes Tim O'Reilly's sppech on the current state of the technology books market. About half of all books sold in America are sold through Amazon.com, B&N, Borders and B&N.com. .NET, PHP and C# book sales are currently growing while Java is falling off. (Although, Java is still the largest category.) Books on Open Source technologies (if you count books on Java and related open source Java technologies as 'open source') dominate the combined sales of books on all 'proprietary' technologies. Sales of books on Red Hat Linux (including Fedora) have dropped off considerably, although the overall sales of Linux books has remained pretty constant. It seems that other distro's and general Linux tech books are growing fast enough to take up the slack.