Conducted by Peter Fischer at Ludwig-Maximilians University and the Allianz Center for Technology in Germany (Allianz is one of the largest insurance companies in the world), the study took a very scientific approach. Published in the Journal of Experimental Psychology, it began with interviewing a number of subjects on their driving habits and how often they played video games that featured driving in a real-world setting. Next, researchers actually compared the effect of playing games like Burnout, Midnight Racer and Need for Speed on the brain. It was found that such games did increase cognitions that relate to risk taking and arousal/excitement. Finally, the study gauged whether these types of driving games actually translated into risk-taking behavior by using the widely accepted Vienna Test System. Sure enough, it was found that men (though not women) were more likely to take risks in traffic after playing these games.
The linked article from Arstechnica makes the good point that the study steered clear of driving games like Project Gotham Racing, Forza and Gran Turismo that take place on virtual tracks in controlled environments. Such games, if studied, might be found to promote increased motor skills and concentration since the goal is to get the best lap time and not run over granny in your Gremlin.
What's worrisome, however, is if the correlation between these types of driving games might eventually give the insurance industry cause to increase rates for gamers that like to indulge in a little Grand Theft Auto.