You can turn your feature/plugin into a company, but more than most startups, you should be incredibly wary of the prospects of those you're piggy-backing to duplicate your product. I had similar criticisms for Rapportive – Google could've "hijacked" their idea at any time. They made it out nicely, but the odds were really, really slim, and still are for anyone wanting to do the same.
I'm not saying don't go for it; just don't be surprised if and when your idea is copied.