I'm somewhat biased, since I wrote it. I think we did a very good job explaining a ton of Android features. We not only described how to use everything, we dug into the details you don't easily find anywhere else. Writing this was a huge effort, researching all over the web, and often digging into the Android source code to figure things out. We wrote 31 chapters and over 1100 pages, with dozens of sample applications to show how it works, and all of the source code is easily downloaded and importable into Eclipse.
We'd love to get feedback on this book, especially as we're already at work on Pro Android 4, and want to know what people still want to see in a book on developing for Android.