Flash, Flex, Actionscript...
I've seen a lot of cool things done with the above, very cool in fact. But it seems like you have to be some kind of guru that started with Flash 4 or 5 to really wrap your brain around Flash's interface. Maybe Flex is better.
Anyway, with Apple not supporting Flash on the iPhone, some are heralding Flash as being dead. Could be, but I'm not so sure, as HTML 5 can't do the things that Flash does, JavaFX is kind of an unknown, and I'm not sure how Silverlight will be accepted long term outside of Microsoft developer shops.
So with that in mind, I think it is too early to write Flash off. If you don't have the cash to outlay for Flash or Flex, check out this open source alternative called Open Pyro. I haven't played with it, but it looks interesting