We’ve been experimenting with something similar at work. Our plan was to move to a two week sprint model, and at the end of every spring the ‘code czar’ for that sprint would examine an SVN diff of every change between that sprint and the prior one. That sounds horrible, but we have four very experienced developers and use jalopy religiously to keep the format consistent, so it really wasn’t that bad. The czar’s job was just to look for any WTFs and bring it to the attention of the group in a final sprint review.
It worked well for the first few sprints. We only fell off it because our scrum master screwed up and let some additional tasks creep into the sprint, then again, and then yet again, and suddenly the two week sprint was over a month and we were staring down the release deadline. But we’ve all agreed to resume the practice in the next release cycle.