HTML5: Up and Running by Mark Pilgrim is described on the publisher's website as a "guide [...] through the important changes" that come with HTML5. The focus here lies on features like the new form-elements, canvas, video and audio integration, localStorage and the applicationCache as well as the microdata component of HTML5. All these are presented with a couple of examples so you should know how to use them for basic operations after reading the respective chapters.
HTML5 is put into perspective with the first chapter that tells some of the history of HTML and how changes to the language have been proposed in the past and how HTML5 came to be. Even if you have known most of this before, it is a nicely written summary.
But back to the present. Sadly the described range of features is far from covering all that is important about HTML5. The author forgot about things like the sessionStorage_, WebWorkers_, WebSockets or the data-attributes. Instead the books contains a couple chapter telling you on how to use ffmpeg and Handbrake to create videos in the codecs and containers supported by most modern web browsers. Space that could have been better used for the new network tools, in my opinion.
Surprisingly the appendix, which contains a short summary on how to detect the new features in a browser (which the author himself summarized with "Try Modernizr"), also contains some of the features not mentioned in the "main chapters". That said, the appendix in itself was in my opinion completely useless since it is basically just a collection of links to each feature and the detection script. The "missing features" received no explanation what so ever.
Another big issue (at least for me) is the writing style as mentioned above. Explaining the first example line-by-line is a good thing. Repeating that with every following example that only contains a minor variation of the solution might end up annoying the reader (as it did with me).
Sorry, was too lazy to also write a verdict :-)