Yes, we do have PMBOK, but this forum is slowly generating its own body of knowledge. Think PM.SE could take a page from Server Fault's book and mark certain accepted Q/A pairs as canonical and list them on meta and provide link there from the FAQ. Right now I'm thinking, for instance, about Q/As on change management, or things like micro-management or estimation of man-hours.
There's nothing I can think of that would make this a bad idea, and aside from that, experimentation with new ideas is a good thing. My suggestion is to start doing this, but start small so you can get feedback from others.
This will tell you more about whether or not this is worth doing and also help get others involved. Hope this helps!