Alas, not our visualization of revert relationships, but someone got slashdotted for doing a visualization of power struggle in Wikipedia:
"todd450 pointed us to a nifty visualization of Wikipedia and controversial articles in it. The image started with a network of 650,000 articles color coded to indicate activity. The original image is apparently 5' square, but the sample image they have is still pretty neat."
The original blog post was here.