This week, both YouTube and Vimeo have announced that they will be experimenting with beta video players that use HTML 5.0. Unfortunately, these beta players are only available in Chrome, Safari, or Internet Explorer with the ChromeFrame plugin (so anyone using Firefox is left out).
As anticipated, HTML 5.0 can be advantageous for video. It includes video as a supported tag, which allows simplified coding and no video buffering if you want to go in and out of a video stream. Unfortunately, at this point not much has been done with HTML 5.0. For example, HTML 5.0 on YouTube does not support videos with ads, captions, or annotations, and also requires a compatible browser.
Via PC Magazine.