An article by Green and Bavelier from the book, Digital Media: Transformations in Human Communication, with the intriguing conclusion that:

Video games currently play a substantial role in our culture as more than half of all Americans play some type of video game. The available research in the perceptual and cognitive domain indicates that such activity is likely to alter a wide range of perceptual, motor, and cognitive traits. Video game play has been shown to dramatically enhance visuo-motor skills. In particular, video game players have been shown to possess decreased reaction times, increased hand-eye coordination and augmented manual dexterity. Video game play has also been shown to improve spatial skills such as mental rotation, spatial visualization and the ability to mentally work in three dimensions. In addition, video game play has been shown to enhance numerous aspects of visual attention including the ability to divide and switch attention, the temporal and spatial resolution of visual attention, and the number of objects that can be attended. The possibility that video games provide a medium that facilitates learning, and thus promotes changes in performance and brain organization, has led some to propose that video games are the teaching tool of choice of the 21st century. The surge in new video games being developed to enhance one particular trait or another is probably the best testimony of the level of excitement in this new field.
There is as yet little research on what this learning may cost -- major performance loss in areas of cognition and/or emotion may also result from gaming. Nonetheless, "in many areas of perception and cognition, video game experience leads gamers to possess perceptual and cognitive skills far beyond those observed in non-gamers."