Seriously, the majority of people on this thread does not know what they are talking about.
As a flash/Actionscript developer:
1) Flash content will continue to work on mobile & tablets - you just need to use Adobe AIR. Adobe AIR is great. I don\'t have to learn a new language to make iOS / Android games. I just do everything as normal like a desktop, and click \'Publish for iOS\' or \'Publish for Andriod\'.
2) Flash / AIR will not die. Many desktop applications are now using Adobe AIR
as the limit of Actionscript 3.0 is very high. You can make a IRC chat program. You can even make photoshop in flash (See: Pixlr) with layers, lots of tools, basically 95% of the functionality of photoshop.
Even Gamefly Client, a Steam-Like service is using adobe air!!
3) Actionscript 3 is very easy to program and very friendly to beginners, while featuring Object Oriented Programming, Filesystem Access for AIR, 3D acceleration. It is also open source.
4) Flash/AIR will power Console Quality Games and Engines like the Unreal Engine
(Already ported). There is a compiler to compile C++ code into actionscript 3 with minimal performance loss while allowing content to be executed on 99% of devices AND mobile phones AND tablets!
5) HTML5 and Canvas will not catch up. Simple -- speed! Both in performance and developer effectiveness - why spend 5 hours doing something that I can do in 3 hours in Actionscript 3, which is a great language?
6) The language is very elegant and, personally, has the best syntax for programming languages.