Particularly that for a lot of target apps (ie. anything vaguely interactive/animated/noisy, such as games and education products), Flash is the only alternativ

Particularly that for a lot of target apps (ie. anything vaguely interactive/animated/noisy, such as games and education products), Flash is the only alternative if you need to support IE7-9. I am in the process of porting our suite of educational products from AS3 to Haxe/NME/Jeash purely to hit tablets, but it looks like we might have to use it on the desktop too if this exodus keeps up. Note that Flex and the AS3 compilers are now an Apache open-source project, it's just the player that isn't.