The Ongoing Role Of Flash On The Internet
Flash already has an important role on the Internet when it comes to general interactive applications, games and video.
Then there’s HTML5, which is supposedly going to replace many instances where Flash would otherwise be used. YouTube has been experimenting with using HTML5 instead of Flash. However, there is not yet any reason to believe that HTML5 and AJAX technologies will become a significant threat to Flash. The fact that HTML5 is an open standard doesn’t automatically put a halo on its head and a path to RIA domination, even though that may happen in the future.
Then there’s the ongoing Flash accessibility issue. Sure, Adobe has its fair share of problems and yes they still have, but they are concerned about accessibility and have been making improvements over time. For example, can screen readers read SWFs? Yes, they can. In fact, to provide accessibility developers can even provided built in readers and voice overs recorded by real people. Can users tab through components? Yes. The problem is becoming less of an issue of Flash itself than an issue of inaccessible design by developers. Remember, you can write inaccessible AJAX too.
The more relevant question regarding accessibility is now becoming “Can Adobe provide developers with easier ways to implement accessibility?” instead of “Is Flash accessible?” Flash today isn’t the same as Flash 10 years ago, and I’ll bet you Flash in 10 years won’t be the same as Flash today.
Finally, while the Flash Platform is not open source, the SWF file format specification is open and free of charge to anyone. Yes, that includes you Apple!
I might be wrong, but I think Flash is not only here to stay, but we’ll see more diverse applications of it in the future. But I’m not betting on this one 
The thing is, don’t dismiss the technology.
http://www.adobe.com/accessibility/