Just because someone is good at WoW, or has great 'camping skill', doesn't mean that they will be the next greatest business leader. There's definitely such thing as burn-outs, losers, slackers, etc. within the gaming community..
The flip side is that there are those who will grow up gaming and be able to learn from their experiences, wire their brains to think strategically, and succeed in life using the skills that they've been able to develop based on the way they have begun to think in life. It isn't A=B here.. it's A leads to B which allows for C.
I come from the text based MUD world of old, and I think that the interaction between the 'characters' and, late at night the regular people over the channels, does indeed increase your people skills. If you're a d!ck, people will tell you, and you'll learn.. if you can't make up your mind and do something, you'll be killed, looted and it'll suck.. so there's your problem solving/decision making skills.
I think the crux of this is the MMOG aspect of the games. It's not the single player Halo 3 gamers of the world that will benefit from the games, but those who understand that 1) it *is* just a game and 2) have the ability to transfer the skills in an abstract way to real life situations.
No matter what, John Doe won't end up being a CEO just because he's a gamer.. there are other aspects of his personality, character, abilities that are prerequisites to the position.