I own the first edition. It's a decent, high-level overview of the changes since HTML 4. It assumes that you have a good understanding of CSS and JavaScript also. However, I don't know CSS or JS and I still learned quite a bit from the book based on the fact that I understand programming concepts in general to have a decent idea of what the JS code is doing.<p>Overall, the first edition was a little lean on content, but I saw today that the second edition was out and is about twice as long, so that may be improved.
I was given this book last Christmas. It's a great overview of HTML5's features. I also met Bruce Lawson in London earlier this year. Definitely worth checking out.
There's a lot of HTML5 books, yet the standard is a draft, and new drafts to that draft come weekly.<p>Now, I'm not saying the books aren't useful - they are.<p>But it's about time to make it a standard and work on HTML5.<p>It's what _forces_ browsers to all have a very short development model, btw.