Unfortunately the term "addiction" has been watered down through use in everyday conversation. We describe Facebook and iPhone games as "addictive" with no negative connotation implied. But the truth is, an addiction is a very serious condition, usually in which you experience physical or severe mental/emotional anguish when you go an extended period without whatever it is you're addicted to. Under that definition, as frob said above, you're talking about a very small percentage of the population. And the truth is, if you were addicted to anything, it's likely your life would bare much more serious signs of it than "I'd rather play Halo than go out and play tag." You'd probably have much larger social issues that prevent you from holding a job for too long in any field, let alone the highly competitive games industry.
So, I'd be as bold as to guess that the number of industry personalities who are "addicted" to games is very close to 0, if not 0.