A common point of discussion and debate with developers and a point of confusion, lack of accessibility and cost discrepancy for nearly everyone else.
Here is a site which aims to settle the score. http://flashvhtml.com/
Deep Links to both versions: http://flashvhtml.com/html/ http://flashvhtml.com/flash/
This points out the obvious similarities in experiences across both Flash and HTML5.
Would be interesting to see a breakdown of costs for both.
What is particularly interesting is how this plays into mobile, which would obviously naturally favor HTML 5 to work across both Android and iOS.