Aiming to act a bit more like Wolfram Alpha (and perhaps become the service Ask Jeeves always dreamed of), the Knowledge Graph already contains 500m objects and 3.5 billion facts, making us wonder how many facts there are on the World Wide Web in total.
With the information coming from public sources including Wikpedia, we'd also say that the Knowledge Graph might be a good overview of a subject with interesting links but we wouldn't rely on it for now.
As we said, this new search feature is kicking off in America but we're sure the big G will see fit to extend the fun to the rest of the world before long.