No, seriously. Post an idea. :)
If you look down at the lower right corner of this browser window, you should see a little red "light bulb" icon. Click this to display a UserVoice-based "Post an idea" widget. You can (and should) use this widget to provide us with ideas for improving "Windows 8.1 Book."
This isn't the only way to provide feedback, obviously: You can email us, post comments on any of the posts on this site, or hit us up on Twitter too. But we're serious about making a book that readers want and find useful. And that means ensuring that we cover the topics that matter most to you. And this widget is a neat way for people to post ideas and then vote on others' ideas.
The context here is that we basically see the 1.0 version of this book as the Windows 8.1 equivalent of "Windows 8 Secrets" from a content coverage perspective. But we intend to go beyond that and cover more advanced topics too. This is one way to make sure that we get there.
In the meantime, we'll be slogging through some material that many will find pretty basic or obvious. But this stuff is the foundation, the glue, the stuff that new users, or those new to Windows 8.1 at least, will need first. Once that's in place, we're going to move forward.
So let us know what you want!