Jonathan Blow (the author of the Braid game) gave this talk on September 27 2010. It's about addictive elements in games such as FarmVille and how that may not be so swell, all things considered.
The talk is about 1 hour 45 mins long; download only, no streaming.
Direct links:
MP4 download: http://edtech.rice.edu/cms/?option=com_iwebcast&action=view&format=mp4&title=CS+Colloquium%3A+Video+Games+and+the+Human+Condition&uri=http%3A%2F%2Fwmdp.rice.edu%2FComputerScience%2FCSBlow-27Sep10%2FCSBlow-27Sep10.mp4
MP3 download: http://edtech.rice.edu/cms/?option=com_iwebcast&action=view&format=mp3&title=CS+Colloquium%3A+Video+Games+and+the+Human+Condition&uri=http%3A%2F%2Fwmdp.rice.edu%2FComputerScience%2FCSBlow-27Sep10%2FCSBlow-27Sep10.mp3
PPT slides: http://number-none.com/blow/slides/games_and_the_human_condition.ppt