I bought Dragon Magic as there was not really any other D&D books out to buy in the local game store that week; I thought it might be a let down after Races of the Dragon but was pleased to find it a really great little book with lots of cool things inside.
The Dragonfire Adept and various feats and creatures have all made it into my next campaign for sure. My one gripe is that it could have included more sorceror stuff.