Some notes from the moock site:
Since its inception, the Flash authoring tool has stored documents in a binary source-file called .fla. Historically, interchanging source with the Flash authoring tool has been virtually impossible for third-party software because the specification for .fla has never been public. But things are changing in the next version of Flash. Flash CS4 will be able to export *and* import a new source format called XFL. An XFL file is a .zip file that contains the source material for a Flash document. Within the .zip file resides an XML file describing the structure of the document and a folder with the document’s assets (graphics, sounds, etc). The exact details of the XFL format are not yet available, but Richard assures me that Adobe intends to document them publicly, allowing third-party tools to import and export XFL.\
This means that adobe flash based compoents are continuing the trend towards open source mentality and implmentation.
Flash language, Actionscript is continuing the trend from version 3 towards Java-like semantics and structures. What this effectively means is that bigger, more complex projects can be coded in flash with less pain, probably to accellerate their push onto the desktop.