Documenting feature implementation in browsers means aiming at a moving target, so the best I can do is take a snapshot. When considering whether to use one of the features in this book, always check the following sites for the most up-to-date information:
HTML5 Please, http://html5please.com/
The CSS3 Test, http://css3test.com/
The HTML5 Test, http://html5test.com/
Can I Use…, http://caniuse.com/
When I started this book midway through 2012, I took a gamble on which features I thought would be best to cover, including not only those that had already been well implemented but also some that I thought stood a good chance of being implemented when the book went to print (or soon after). As I write this in early 2013, it seems that the pace of wider adoption has been slower than I anticipated for some of the features contained in Internet Explorer 10 (such as Grid Layout, Regions, and Exclusions), but everything else is proceeding apace.