Yesterday Google announced that future versions of its Chrome browser would not support the H.264 video codec. This codec is seen by many as the only viable alternative to Flash, and support for it in browsers as the default implementation for the <video> tag was thought to be the future of the web. Google's decision to drop H.264 in favor of WebM yesterday has left many feeling upset, decrying the decision as bad for the open web and a sign that Flash Player will not actually die in the near future, but live on.
Yet Google's decision is ultimately unimportant to the open web. There is one simple reason for this: Firefox doesn't support H.264 either. Neither does Opera. Firefox has always supported WebM and other open codecs over the licensing required for H.264, and as you probably know Firefox's global usage dwarfs Chrome easily. In some places Firefox and Opera actually have the highest penetration (Germany and Korea respectively.) That Chrome, a fast growing but relatively new entrant to the browser world, would not support this codec as well is frankly unimportant.
On the Windows platform, Microsoft has tried to help H.264 adoption by authoring an extension for Firefox that allows Firefox to access and use the H.264 codec included in Windows 7. Ostensibly they could do the same for Mac, and Apple (or anyone) could author similar extensions for use on OSX.
Problem solved, right? The open web is saved! Not so fast. Most Linux distributions don't have and likely won't include native support for H.264. It's hard to view any standardized implementation of <video> that doesn't support Linux as "open", as it's arguable that no piece of software better represents "openness" than the Linux OS.
In conclusion, while HTML5 is a wonderful improvement and the "open web" continues to be an valuable goal, a realistic view of the situation shows that there will never be one solution that satisfies every browser's requirements. This is likely to be the case with CSS3 as well as HTML5 features itself (see different implementations of offline storage and application caching).
Private products that provide "proprietary" work-arounds to browser inconsistencies remain your best option for achieving the "write-once, deploy everywhere". HTML5 might make plugins like Flash a little less necessary for viewing animations, playing games, or getting rich interaction, but on more complex problems like video Flash Player is still the most widely support and close to ubiquitous solution around. This was true last week and will still be true next week, regardless of anything else Google might do.