The “Plus Box” feature, which was spotted in November and which Matt Cutts blogged about in December, is now an official feature.
It appears at the top of search results for stock information and maps, at present, with a “+” next to a link that expands into a full stock quote and graph or map. (See an example in a search for [Apple].) Tests for a video Plus Box have been spotted, but Google does not mention them in this announcement, other than to promise that the Plus Box will be used for more types of information in the future.