This article gives us a bit of insider gossip about Flash CS5. There are a few typos in it, and for someone whose English isn’t up to much, like me, it was enough to bring tears to your eyes.
A few things I paid attention to:
Adoption rate
Looking at the current state of the Flash platform, FlashPlayer10 installs are still climbing, and the new figures are expected to reach over 90% coverage in the near term.
Flash CS5 features
The biggest news for developers is that Flash authoring is finally integrated with FlashBuilder. If you’re using Flash CS5, you can export a new FlashBuilder project through a new export dialog.
If you work in FlashBuilder, it goes the other way too — you can point it at a FLA and it will build a FlashBuilder project for it. What’s more, Flash projects can be tested and profiled with the built-in FlashBuilder. Put together, these form a complete and efficient workflow: you write code in FB, then export/test your files with the Flash IDE. (Mousebomb: personally, a lot of my projects right now are code in FDT + export and test in the FLASH IDE, so it looks like the CS5 era will be even more convenient and efficient) 
Editing in the Flash authoring environment has been improved as well, and the team has shifted its focus back onto “making Flash more user-friendly”. There’s now a new code samples panel, aimed at people learning AS3, which is something of a callback to how useful behaviors were in older versions. Click any of them and the code gets added to the timeline, making that part of the job easier for beginners — but since it’s configurable, it’s really more of a built-in Snippets panel for Flash, so you can stuff all kinds of things into it. 
Finally there’s a section on Flash Mobile upgrades that doesn’t really affect me for now, so I’ll skip it. Now that 3G is everywhere, mobile online games are about to become a hot topic — maybe I’ll need to dig into that someday.