A Casual Revolution is a nice attempt to explain a constantly changing product like gaming and to his credit the author does a good job of explaining at least one definition of the difference between casual and non-casual gaming and even points out how games can overlap between these two fields.
However throughout the entire book he gives half truths and blatant lies (he's not trying to lie to be fair to the author he simply doesn't know any better) as he tries to explain gaming when he blatantly tells the reader he hasn't played much of any game spanning between pong and tetris up until the Wii's release, even going as far as inferring that casual gaming didn't make any progress between these two stages (he doesn't say this, I just get that vibe from reading the book). To be quite honest this seems to be an outsiders (non-gamer for most of gaming's growth, and a non-developer) looking in on a hobby he hasn't participated in for around a decade and as such there are much better books out there (A book of lenses is a new one I particularly enjoyed if your looking for game design tips).
Do yourself a favor and look for a different book other then this unless you really want outdated information on casual gaming for some reason