some community/discussion/voting system?

[frnsys]

for instance, for contributing better summaries/explanations, for determining which images are the best/most salient, for determining which stories are most important (in addition to other proxy metrics such as views/shares for the argos pages and also for the articles that compose the argos pages).

[ameensol]

I've been looking at moot.it for similar purposes. Doesn't do voting, but might help for discussions. Also only for the web.

[frnsys]

cool – though they don't seem to have native iOS support?

[ameensol]

True, you could try seeing how this guy does it for newsblur, there code is on github here.