While the new, robust import of Photoshop and Illustrator files in Flash CS3 seem to be getting a lot of attention, often overlooked are the great improvements to the export of video from Flash. Older versions of the Flash IDE allowed export to Quicktime, but nested symbols could render strangely and most importantly, no ActionScript-generated animation would render out at all.
I recently had the opportunity to create a compilation DVD of all my short films over the past decade or so and these did include some lengthy animations. I had a very difficult time transferring the animation to video but finally found a freeware solution which could render a swf into a number of different video formats. It worked out but there were still some oddities even with this process. Really wish I had this new functionality a few months back!