Considering that HTML5 isn't a standard yet, it will be a while until everything can be supported by all browsers.
It really comes down to how well all of these scripts can be supported by either application interface. Flash is also rather easy to learn since shapes, gradient, and text can be developed with or without code. The browser is only dependent on one element to support the use of Flash and that is the Shock-Wave plug-in.
To me it would be a long while until full compatibility can be considered for HTML5 to replace Adobe Flash.
HTML5 can still be used as to improve the websites design & interactivity for now.