I've only just recently got a bit deeper into OpenGL and I don't really know what all the changes are in comparison to the previous version(s) both in the Book and OpenGL.

I guess there is a lot of refactoring to do, checking if it really is the correct usage, make sure everything is correct and make it properly readable. These things take time obviously.

Although I prefer learning from books, I don't usually pre-order anything. When I want it, I want it asap so I can use the new info asap! Thing is, most of the time this new info is already available on the web before a book is out, making the waiting for the book somewhat obsolete for pure information purposes. Of course, this is not always the case and you will probably get more info out of a book than you can scrap together from different sites. (This is why I prefer books for new subjects).