Jenson Button entered the 2010 Formula One season as the Reigning and Defending drivers world champion because he had won the 2009 drivers title. Sebastian Vettel won the drivers world title in the 2010 season from Fernando Alonso by just 4 points. Vettel has been the defending world champion ever since because he won the titles 3 consecutive times in 2010, 2011 and 2012.
The current reigning F1 world champion of 2010 is Sebastial Vettel. He drove for the Red Bull Racing team.
He is world number one, and will be the defending champion for a few events in 2010, but he is not the reigning champion of any major.
Sebastian Vettel
The current F1 world champion is Sebastian Vettel from Germany. He is the youngest ever world champion.
Sebastian Vettel (GER) - champion in 2010 and 2011.
Italy are the reigning champions, after beating France on penalties in the final in Germany in 2006.
The 2010 reigning champions are Spain.
As of July 2014, Sebastian Vettel is the current Formula One World Champion driver, having won the championship 4 years in a row: in 2010, 2011, 2012 and 2013.
Spain is the world champion.
Neil Robertson is the snooker world champion 2010.
In 2010 England became the champion of T20 world cup which has been held in west indies.
Sebastian Vettel for Red Bull Racing