1. New forms-based development paradigm. Since folks are starting to use Flash for forms and components in the same way they used Java AWT and Swing in the past, Macromedia added the option of using a forms-based environment rather than a timeline-based one.
3. Improvements to the standalone projector. I really hope they put some effort into this. They are allowing overloading of the right mouse-button (or are at least allowing you to modify the right-click menu, I'm not sure). Hopefully they'll keep up the trend to the rest of the projector. Given their new push for Flash as a first-class app development tool, making good standalone executables is a must. There are plenty of projector-replacement-vendors out there already, so it's not too big a deal if the projector is still lame.
4. Faster performance. I've been using the beta player for a few weeks now, and performance is definitely better, but it'll be nice to see performance continue to increase, thus allowing better arcade games with Flash.
5. Scriptable environment. Looks like you can now write improvements to the Flash environment itself using ActionScript. This'll probably open the door to lots of third-party interactive behaviors.
6. Cell phones! The pro edition's coming with the ability to develop for an on-screen cellphone (several cellphone skins included), and you'll be able to develop for the new "baby flash player" designed for cellphones. This is still kinda sketchy, but the screenshots show Flash content running on a Nokia 3650. That'll be nice, as I'll be able to make cellphone versions of the games without having to do a lot of rewriting. My only question is how easy it'll be to make a standalone cellphone app. Will there be a standalone projector-builder, or will the user be required to download the player directly? My prediction is that the player will at first have to be downloaded separately, but third parties will make projector-builders that'll allow you to make a standalone app. This is basically what happened with PocketPC Flash --at first you were required to install the player separately from the app, but now there are buiders that'll make your SWF into a standalone EXE.