I keep thinking something useful could be achieved without getting too formal or needing something as strict and complex as Prolog.

Looking at how well a site like Stack Overflow is working gives me hope of a happy medium between rigor and usability being possible in the future somehow.

It combines a whole bunch of ideas from social sites such as voting, points, awards, wiki style editing into an effective solution. Far from perfect but useful which as about all you could ask for I guess.

It would also be interesting if a company like Disqus started experimenting with features in this area.