Much has been made of how HTML5 will kill proprietary media tools and players from Adobe Systems and Microsoft. Web advocates claim that with the much more sophisticated audio, video and animation tools in HTML 5, the web will no longer need proprietary plug-ins from outside vendors.
While you'd be hard pressed to find anyone outside Microsoft or Adobe who thinks that a totally open web, where anyone can build anything without needing outside tools, is a bad thing, making that vision a reality will likely prove much more complex than even its most taciturn supporters are willing to admit.
HTML 5 is a nice dream, but the practical realities of web development mean that the dream faces a serious struggle becoming a reality. And, even if it does end up winning, it isn't likely to happen any time soon.
There's no question HTML 5 is a revolutionary upgrade for the language that powers the web. Much of the specification was designed to plug precisely the gaps Flash and its brethren currently fill - like the animation API tools for the Canvas element, Local Storage, Web Workers and the audio and video tags.
Eventually, when browser makers fully support all that HTML 5 has to offer, it will be possible to build the powerful web applications that today require add-on technologies like Adobe Flash, Microsoft Silverlight or Sun Microsystems - almost Oracle - JavaFX.
However, to suggest that HTML 5 means the death of Flash or Silverlight is imminent entirely ignores several practical realities that go far beyond simple problems like browser support.
There are other problems HTML 5 faces in its quest to replace the current crop of single-vendor tools like Flash. The specification recently received a significant blow when its creators announced that it would not specify a default codec for the video tag.
The browser manufacturers involved in the W3C working group developing HTML 5, couldn't agree on a universally-implementable video codec so, at least for now, that's not part of the official spec.
That means browsers will continue to implement the codecs and APIs ordained by their owners as they've always done, leaving developers and customers to pick a side or go to the additional cost and effort of supporting different players.
In short, HTML 5 video isn't going to kill Flash video players any time soon. YouTube and other major players in the web video world face the same conundrum that drove them to Flash-based players in the first place - offer multiple videos based on browser configuration or use Flash for a "just works" user experience.
And don't forget that Flash is more than just a video container, it also powers much of the animation on the web. That's where the new Canvas APIs are supposed to come in - they give designers a way to create the sort of sophisticated animation elements that Flash is often used for today.
Ready made tools
However, at the moment there are next to no developer tools for creating animations using Canvas.
Take away the Flash development interface and the two technologies would be competing on an even playing field, but so long as Flash makes it infinitely easier for non-programmers to create animations, don't expect those same people to be in a rush to abandon what they know.
And if the developers and designers building the web aren't making the transition to HTML 5-based solutions, don't expect Flash and Silverlight to die off any time soon.