I think video games can help, but doesn't do FIRST robotics driving justice for choosing a driver. The best robot drivers make the best robot drivers, some just may happen to have great racing game skills.
As far as when I am picking a driver for my team the first thing that I look at is the persons sports background. From what I have found drivers with a background in sports turn out to be better drivers because they understand the meaning of pressure situations. Also as far as communication aspects between myself and my drivers they don't forget about the fact that they are playing a timed game and don't attempt to question decisions that are made during the game.
There are many things you can look at for the driver but the most important thing is getting someone to practice. The driver is the most important position on the team, you could have the best robot out on the field but it is useless if you don't have a good driver. My advice is who ever has interest right now give them a robot to drive, set up some cones in an open space and get use to the controls of the robot.
1114 has posted a great list of
requirements for a driver on their website. 612 uses something a little bit similar but I agree with many things that they go through when they pick their drivers, so far it has seemed to work.