Basically they meshed all of the "new" into the old and hoped it would make up for the huge screw up. You CAN have that powerful wizard or cleric again like Raistlin or Goldmoon. You have the grandchildren of those companians running around as well. It details a few of those in the book.
You've got a faction of draconians solidifying a position, completely independant and wanting to stay that way, led by a General Kang. I find that interesting myself. They hunt down anyone who comes near them, "good" or "evil". Humans are just as likely to be slaughtered as elves or ogres. That could make for an interesting story in and of itself.
They incorporated a small..very...small section on the continent of Taladaas (sp?) that never came up within the novels as far as I read.
They basically gave descripitions of all the places incorporated into the novels and set it in "modern" times allowing you to go to the places you read about. Then threw together a section, not a very good one IMHO, on how to use the other time periods. However, investing 10 dollars at a used book store can get you a handful of novels to read which would give you the background for a different age.
I THINK that Weiss is the one heading up the Dragonlance project and is the major writer for the book. I'm pretty sure she decided to do her own thing on the license they wrote for the D20 system and keep her world alive. I don't think her partner Hickmann joined in on it though. Overall, I like the book and the world it's describing.
They go into a whole new batch of "new dragon overlords", just in case you want them and missed the dead ones.