The point, however, is that social news sites (so far) are not replacements for editorial front pages. They exist solely because the mainstream news sites aren'

The point, however, is that social news sites (so far) are not replacements for editorial front pages. They exist solely because the mainstream news sites aren't very broad (10 stories are 50%, sounds like the long-tail book again). If I want LolCats, I go to digg. If I want news about Iraq, I'll listen to NPR. If I want something about hackers, I'll come here. Comparing them to eachother is basically a waste of time, except to indicate that there might be a market opportunity (is there a community not being served by ANY of the outlets listed?)