Gamification is simply the application of a ton of learnings (and in some cases, pure intuition) about how humans behave, what drives us, and how to keep us engaged. In terms of "stick badges on it and people will keep using your product", gamification is not going to hang around all that long, ruined by poor execution and over-exposure (as with any UX trend).

However, the trend of humanification -- designing for and by humans, taking us away from an age of faceless software -- is well underway, and I don't think that's going away any time soon. I also think that's a Good Thing.