By no means is this review indicative of the setting as a whole. This sourcebook just really doesn't do a whole lot, other than provide a sort of jumping off point for other sourcebooks. It feels kind of bland, and not really able to tackle in depth much about the setting.

It doesn't look or feel as polished as the Forgotten Realms Campaign setting, or even Eberron for that matter. While this is the only WOTC book in the DL line, it really feels like the book was almost designed to just usher people into the SP/MWP books. If you aren't already a DL fan, this book won't likely make you one, and if you are a fan of the novels looking for sourcebook material, it will fall a little short.

The book tries to do too much with too little, and its not polished enough to really cover its flaws.

If you are going to run a campaign in Krynn, you will likely want this, but I'm not entirely convinced that you can't puzzle out what you are missing if you pick up the other DL 3.5 books, exept that a few key concepts (like the draconians) seem to be reserved for this book alone.

Those of us who discovered DL during the days of AD&D, before the advent of The Chaos Wars, are apt to be sorely disappointed by the lack of substantial War of the Lance material. The Pre-Cataclysm period also gets barely a nod. Although Krynn is every bit as engaging a world as Toril, you'd never guess by comparing the two campaign settings.
That said, if you're looking for a War of Souls or Age of Mortals era campaign, this book provides a decent starting point. Excellent racial information, plus a few very useful prestige classes, combine with regional information to create a solid groundwork for campaigns anywhere on Ansalon. Unfortunately, it is difficult at times to connect the various regions geographically; political maps are small in scale.
Where the DL CS truly shines is as a general reference for DMs and players alike. It seems that WotC put this book together intending the information within to be used in non-DL campaigns. The aerial combat section is detailed exquisitely, and there are enough tidbits of mythology to help flesh out homemade societies in other worlds. Lots of campaign ideas in here, even for non-Krynn DMs.
Ultimately, it's good that the folks at Sovereign Press are putting out further DL references for edition 3.5; as a campaign setting, this volume barely scratches the surface.