If there's ever anything that irked you about the Storytelling System, this is a book that lets you toy with the mechanics on pretty much every level imaginable, from the character creation rules to the way combat works, all the way to getting rid of Virtue/Vice and Morality and replacing them with alternatives.
The things that I liked the most, however, were the rules that added to and expanded the game as opposed to revising what currently exists. There's a social combat system called Sway that seems rather solid, so much so that I may adopt it for use across all my games. Another mechanic that I really enjoyed was called Anticipation, which once per session lets a player make a roll to insert a flashback scene explaining how their character was smart enough to have anticipated their current predicament and taken steps against it.
The final chapter goes into alternative takes on a chronicle, from a World of Darkness where mortals are aware of the supernatural to a dozen different flavors of apocalypse scenarios. Finally it presents a modern fantasy take on the World of Darkness, which oddly enough presents a brief version of a unified cosmology for all the game lines. It is by no means the official word on the nature of the World of Darkness, but it is certainly interesting enough to merit an experimental play session.
Probably what I enjoyed the most, however, was the Appendix, which featured the various writers waxing philosophical on their favorite house rules, some of which were in the vein of "I Hate Experience Points: So Here's How to Get Rid of Them," but all were interesting to read, and all presented valid reasons for their changes.
I've heard rumors of a PDF expansion to this book that will contain Sci-fi material. As much as I look forward to that release, I must say that I was very satisfied with what I found in this book. The Afterword has made a lot of fans worried that White Wolf is getting out of the RPG business altogether, and the lack of communication from the once talkative company has been of some concern, but I've been assured by multiple sources that they are merely changing their publishing model; core rulebooks for their game lines will be 'evergreen,' meaning always in print, while their supplements will be moving to PDF, and later Print on Demand once their setup is complete. But as far as the last traditionally published supplement for core World of Darkness goes, this was a pretty solid release and I feel that it was well worth the wait.
Now if we can just convince White Wolf to stop using scribendi for their editing...
[4 of 5 Stars!]