Alright, I\'m confused by all the buzzwords and press release bingo going on.
What is the difference between Flex and Flash?
The way I keep it clear in my mind and explain it to others is as follows:
Choose the right tool for what you want to create.
If you want to write an APPLICATION using Flash technology, use Flex.
If you want to create an ANIMATION using Flash techology, use traditional Flash.
Flex is optimized for application construction (but you can create primitive animations using states) and it compiles into a SWF.
Flash is optimized for animation construction but you can also create applications with some extra work, and it compiles into a SWF.
Once you have your SWF you can play in your Flash player, although Flex requires Flash 9 or higher.
In conclusion
Application -> Flex -> SWF
Animation-> Flash -> SWF
Hope this helps.