Hey,
in order to sanity check the code we have written in the Wikidata project, we have asked an external company to review our code and discuss it with the team. The effort was very instructional for us.
We want to share the results with you. The report looks dauntingly big, but this is mostly due to the appendixes. The first 20 pages are quite worth a read.
Since the Wikidata code is an extension to MediaWiki, a number of the issues raised are also relevant to the MediaWiki code proper. I would hope that this code review can be regarded as a contribution towards the discussion of the status of our shared code-base as well.
I will unfortunately not be at the Hackathon, but a number of Wikidata developers will, please feel free to chat them up. Daniel Kinzler is also preparing a presentation to discuss a few lessons learned and ideas at the Hackathon.
The review is available through this page: < http://meta.wikimedia.org/wiki/Wikidata/Development/Code_Review%3E
Cheers, Denny