I'd be surprised if I wasn't one of these alleged puppets. Of course I'm more likely to vote up something that someone mentions to me in IM, because I have to see it before clicking the button.
I can see how this looks like sock puppets. You've got a few dozen users that always upvote the same articles from a few dozen other users, and are much less likely to upvote other articles. I'm not sure the best way to know that we're all humans. If there were fewer people using/excited about/writing about ruby on rails, then the behavior would appear very similar, I suspect.
The term "gaming" is really vague. It's not at all clear how "this is something interesting that I'd like to share and discuss" is much different from "this is something that I'd like to get people to look at." It seems to me like the ultimate purpose of a site like this is to be gamed in a particular way by a particular population.
Just would be interesting to be more transparent.