It starts with a couple gentle introductory chapters, followed by a very dense syntax dump in the third chapter. The intended reader may survive the sink or swim approach, but I suspect they're more likely to give up after that chapter. The now requisite Ajax chapter towards the end seems quite out of place, again because of the context of non-programmers just picking up scripting.
Strengths: good cookbook for experienced programmers, sprinkled with useful tips (albeit buried in code explanations).
Weaknesses: way too much information that a learner has to take on faith, narrow column format drastically reduces code readability.