So for those that having seen it yet, YouTube have launched Auto-Captioning for their video content. Mashable have a great article discussing the launch here.
This launch is being billed as a way to create greater accessibility for the deaf and the rest of the internet and quite frankly it is. I have a friend who is a early childhood teacher at a deaf school and I know how important break throughs like this are.
However I think there are far greater possibilities for this technology than just accessibility. Search engines rely on text to understand what is on a webpage. If through captioning or embedded metadata search engines can understand what a piece of web video is about, it can then start serving up video content in the organic search result, like they currently does using alt tags on pictures.
Adobe showed off the speech to text metadata embedding when they launched CS4. they used the Obama acceptance speech on the New York Times as the shinning example. But with Google now able to index text from Flash and text embedded in the Flash video, it can’t be long before the text of a video is indexed as a part of content.