Why isn't there a place that links to a given paper so that discussion about the paper can be centralized? It could also contain links to papers that link to that paper, among them would/could be the failure to replicate information, adding to the discussion. And I don't really mean a topical "this is what's new" site, I mean a historical "This is the paper, and this is what people have said about it." sort of site.
This seems like a fairly elementary idea. The only seeming difficult bits I see are:
a) Getting (legal?) access to these papers.
b) Dealing with a large number of papers (millions?).
c) Authenticating users to keep the discussion level high.
d) Moderating the discussion in a way that doesn't piss off academia (impossible?).
e) Keeping the number of these sites (competition, if you will) low so that the discussion is not fractured between them.
It would seem like one of the "Information wants to be free" sites that host the papers that everyone shares with each other would be a great place to start something like this.