I actually went to the seattle release of Flash MX......i'm not to the point of being able to design sites in flash yet but MX does have some great stuff: Instead of having to build scrollbars and stuff they are now in a "components" menu......so you just drag and drop it for use, plus they are reskinnable so you can make 'em look how you want. you can also specify behaviors.
also MX can do video, there's also a drag and drop video player that's reskinnable. Plus there's an included video compressor: at the launch the speaker had a video @ 2.5mb, when compressed the whole site including video was around 450k.
Plus for ordering pages you can change your inventory, etc and the page recalculates in real time instead of having to refresh and go back to the host server....great for online businesses. it'll calculate tax and stuff too automatically.