How pattern feedback on a wiki might work… 
Here's how I think feedback and revising a pattern description based on that feedback might work: The pattern is broken up into its sections, and for each section one can provide feedback in the form of posting comments. At some point of time, the feedback is incorporated into the next revision of that pattern section. The new section overrides the old. I'd say the new revision will be a new page rather than a revision of the existing page so that the comments can start fresh on the revised section.