I have been keeping track, as best I can, of books bought through the Virtual Bookstore in the Sessions db.  The count is shown in the view, if you are interested, and you can click to sort by that column.  When you do, the results are interesting.  The top book, by far, is Mastering XPages, but I thought I'd list the books here that have at least two purchases now, more than a week before the conference starts.  You can click on any of the names to find out more, or even to order if you like.

8 copies - Mastering XPages: A Step-by-Step Guide to XPages Application Development and the XSP Language

Authors: Martin Donnelly, Tony McGuckin, Mark Wallace

4 copies - Lotus(R) Notes(R) Developer's Toolbox: Tips for Rapid and Successful Deployment

Author: Mark Elliott

2 copies - Dojo: The Definitive Guide

Author: Matthew A. Russell

2 copies - IBM Lotus Notes 8.5 User Guide

Author: Karen Hooper

2 copies - Just Enough Governance for Notes

Author: Craig Schumann

2 copies - Mastering Dojo: JavaScript and Ajax Tools for Great Web Experiences (Pragmatic Programmers)

Authors: Rawld Gill, Craig Riecke, Alex Russell

Please note that the following two books are ordered directly from Packt Publishing, so please let me know if you order one so I can add it to the total.  I can't see counts of books ordered through Packt, so I rely on people letting me know.

2 copies -  IBM Lotus Quickr 8.5 for Domino Administration

Authors: Keith Brooks, David Byrd, Mark Harper, Olusola Omosaiye

2 copies - IBM Lotus Domino: Classic Web Application Development Techniques

Author: Richard G. Ellis

Is this all a popularity contest? Perhaps, but people had to choose to vote with their dollars to support these authors and choose these books.  As a businessman, and avid supporter of books and authors, I think I'm OK with that sort of popularity contest.