Wow, this is pretty intriguing and may actually be a solid differentiator in the browser space since it probably requires a considerable stored database of speech samples coupled with a decent back end server farm to do it effectively. Hard for the other players to replicate. Clever move Google!

I wonder if they will add this as a standard feature for any text field at some point? It's probably not going to get much sunlight if it requires a chrome-specific attribute on the field.