Adobe edge is NOT a "Flash replacement". It is an alternative for simple animation ie web banners. Flash is still a powerful tool and at this point in web development, and better choice for a lot of things.
Edge may not be marketed that way, but statements like this sound like denial to me: "But as Web development continues to grow and change, Adobe officials indicated they intend to stay aggressive in supporting both Flash and HTML5 with new and enhanced tools for programmers."
With the aggressive anti-Flash stance Apple has taken on all iOS devices, developers are going to start seriously looking for alternatives to Flash. HTML5 is the future. I'm not saying that Flash won't play a part in it, but YouTube's transition to HTML5 is just one of the many signs that Flash is on the way out.
Why would people want to develop a site using Flash when people with an iPad, iPod Touch, iPhone, etc. can't view it?