Jon Udell opines on feedback loops in data rich spaces. The key nugget in the piece for me though, is the description of how Reuters calculates its Heat Index, balancing # of stories filed, # of high priority stories as identified by editors, and # of hits to Reuters.com. This is the type of stuff that should be easily visible in socially translucent communities.
Following up on that, Jon links to a similar hack, with a geographic orientation: newsQuakes. Worthwhile remembering just for the JavaScript library that implements the hovers, although it's unclear how the story calculations are made.