This was a great article with a lot of useful links, and I'm really glad Wikimedia is doing this!
Ryan and Roan have been very visible in the OpenStack community. We're doing similar things with code review and testing using Gerrit and Jenkins, and I'm excited that we have a lot of direct cross-pollination going on there right now. Thanks!
We're running into more and more people who are doing infrastructure-as-a-project and it seems like we all want to share our puppet modules with each other. But when it gets down to it, we've all written fairly non-generalizable modules that work for us but aren't useful to others without a lot of work. It just seems to be something that's encouraged by puppet's syntax and the way people use it.
As another commenter alluded, perhaps if the module forge were full of robust easy to use and extend modules for many everyday tasks, things would be different. I think an ideal configuration management system would be designed around sharing from the start. Puppet keeps evolving, maybe we just need to figure out the best way to use it in projects like this.
This seems like an area with a lot of opportunity.