I think that is what http://www.newsvine.com/ set out to be in the beginning - the curation and verification of submitted content - I haven't thought about it in years though and a quick look at the home page shows that it still isn't very popular and seems pretty partisan.

But I agree, finding a way to crowdsource all three points of journalism without it becoming a mob (see reddit after the boston bombing) sounds like exactly the sort of newsource I would be interested in.