IndyCar Series CEO Randy Bernard called the announcement "an exciting day for the IZOD IndyCar Series and a positive step to start 2012."
He continued: "We've said all along that one of the most important factors that will make the IZOD IndyCar Series successful is having the best drivers in the world, and there's not a person in the world who knows racing that wouldn't tell you that Rubens Barrichello is one of the greatest drivers of all time."
And of course Tony Kanaan, the man whose tweeted invitation to Barrichello to come try out the KV car kick-started the whole thing in January, is thrilled. Just as long as he doesn't end up following his 'brother' around the race track too often during the coming season, that is.
"I am looking forward to the start of the season, I think its going to be a very exciting year," he said.
Barrichello is one of the biggest names to move to IndyCar from the world of F1. The 39-year-old Brazilian driver has 322 Grand Prix starts over an unprecedented 19 consecutive seasons in F1 since his début in 1993, including 11 GP victories.
His most successful period in F1 was the six years that he spent at Ferrari alongside Michael Schumacher from 2000 to 2005 during which time he twice finished as runner-up in the world championship, but during his career he also competed for Jordan, Stewart, Honda and Brawn. The last two years have been spent at Williams F1, but the team announced in January that they were replacing Barrichello with his compatriot Bruno Senna for 2012.
Barrichello's signing is an important tonic for the IndyCar Series, which ended a promising 2011 season with the tragic events at Las Vegas that saw Dan Wheldon lose his life in the season finale.
The series also had to move on from the defection of its star name (in terms of media attention) Danica Patrick, who has moved to full-time stock car racing in NASCAR this year. But if Twitter is any measure of popularity then Barrichello with his 1.47m followers easily eclipses Patrick's 447k followers, illustrating just how much more worldwide interest in the sport Rubens will be bringing with him to IndyCar in 2012.