I see this as one of the evolutionary steps towards automatically created voice-to-text transcripts that will eventually offer great benefit for both Deaf people and search engines.
Last month, Google Research included the voice-to-text capability on the “You Choose ’08” page on the U.S. presidential race. On the “You Choose ’08” page, scroll down a bit to “What did the candidates say?” and you can search for a keyword in transcripts of what the candidates said inside video clips. If you move your mouse over the yellow markers on the video timeline, you’ll see a short text summary with the keyword.
Google Research admits that the automatic transcripts aren’t perfected yet, still I would like to be able to click a link to read the whole transcript. I would imagine that the next step in this evolution would be timecoding the transcript and offer an option to view the the subtitles directly near the bottom of the video clip as it’s being played.