Just want to draw a bit of attention to the new documentation for the Flash 9 preview. It’s all in LiveDocs, so you can leave your comments for the writers involved – this will help improve the final documentation, so I encourage you to let them know what you think. Do you want samples of something? More info on how to migrate? Coverage of a particular API? Let them know!
On the developer center, you should check out:
Exploring the Flash Professional 9 ActionScript 3.0 Preview (an article Peter deHaan and I wrote on how to get started with AS3 in the Flash Preview).