World Cup instant results are probably the most comprehensive OneBox results ever added by Google. They offer so much real-time information that you don't even have to visit other sites. A search for [world cup] shows today's matches and the matches from any other day, group results and a chart for the second stage.
Search for a match and Google shows a timeline, match stats and lineups. Search for a country (for example: [argentina world cup]) and Google shows the latest matches and results.
There are also Google Now cards with useful information and notifications:
To see much Google's results have evolved, here are the OneBox results from 2010:
Here are the results from 2006:
Google doesn't only show interactive results for the FIFA World Cup, it also replaces the Google logo with a lot of interactive doodles: 40 World Cup doodles in 18 days. Too many.
In 2010, Google only used 2 doodles for the opening day and final, as well as a few doodles from the Doodle 4 Google competition. In 2006, Google used a single doodle adapted for the participating countries.