Capturing the aggregate information about what a given community considers interesting is very useful; but it's insane to conflate what the community finds useful in aggregate with what each member of the community will personally find useful. Unfortunately, very many sites have made precisely this insane mistake - practically everyone except del.icio.us, in fact. Consequently we have a whole genre of sites with very predictable signal/noise decay.
This happens because the kind of filtering that a social networking approach to news gives you has some serious flaws. I'm mainly ranting about the Hordes Of Moronic Imbeciles Expressing Their Opinions About You Problem, but two other problems to consider are the Tim Bray Problem and the Cory Doctorow Problem. These guys are each more interesting to the developer community than they are to me, which puts them on my radar way more often than they should be, and in either case this causes a problem.
The Tim Bray Problem is that the developer community pays a lot of attention to Tim Bray, but I have never derived any use at all from any information connected to Tim Bray in any way, and after exposure to a lot of such information, I'm becoming very confident that nothing Tim Bray says about anything will ever make any difference to me one way or the other.
The Cory Doctorow Problem is related, but much thornier.
Unlike Tim Bray, Cory Doctorow often annoys me. The Cory Doctorow Problem is worse for me than the Tim Bray Problem, because Tim Bray is a glass of water when I'm not thirsty, and Cory Doctorow is a winning lottery ticket buried under a hundred thousand yipping chihuahuas who all need to pee. I could really use that lottery ticket, but I really don't want to deal with those chihuahuas.
