LongTailVideo, makers of the popular JW Player (a video player for Web pages), just posted a long article titled “The State Of HTML5 Video.” I used JW Player on a couple of projects and was quite pleased with its usability and reliability. My experience was with using JW Player to present Flash video, but the player has since been modified to serve either Flash content or HTML5 video, which is great. Towards that end, the article presents the current state of HTML5-related features and functionality, with lots of stats about browser compatibility, what attributes and video formats can be used, and so forth.
If you present video on Web sites, whether you use the JW Player or not, it’s worth checking out to know where things stand. LongTailVideo intends to maintain and update that article as changes in the industry (such as statistical changes and the like) evolve.