The quality of the book is exceptional and it is all taught in a bright, colorful and engaging style which I think works really well. I am currently working my way through the book and I hope that when my daughter is a little older she can also start to learn from this book and others like it.
The programming world these days seems to mostly lean towards the web, so the choice of technologies in this book is sensible and should hopefully help to create our future software development workforce. Learning at a young age from resources like this or even mature resources like Pluralsight and Lynda is much more valuable than formal school education as it is more fun (in my opinion) and encourages kids to experiment instead of fitting into a rigid curriculum.
Go and get a copy of this book for your kids, or buy it for friends who have kids and help to inspire them, it really is not an expensive book which really helps lower the barrier to entry.