I wouldn't BLAME social networking, because there are ways to use them to your websites advantage, for example: an IPB script so that when you post a new thread it updates your status to "has just created a new thread "thread name" at
http://www.bit.ly/whatever"I think social networking can only help online communities, obviously, if used properly.
I am a web designer at an online DJ store and when I'm marketing, I often use Facebook, twitter & myspace to target our consumers, even though you're just "Becoming a fan" of a company e.g. Apple, Microsoft, Sony, Adobe etc. they are still going to use their thousands of fans to their advantage to advertise... so why other websites don't do this to help their community grow I don't know.
I know P2L has a group on Facebook, not sure about a fan page, but the fan page I created for my company with enough status updates and sharing, I went from 0 Fans to 900 in around 2 hours. It's not up to around 15,000 since last weekend.
It's all about working together, websites are going to come along that may crush your website, but if you work with them instead of against them, you'll find it will be a whole lot of an easier ride to just take advantage of them!
Also, yes, twitter is the biggest fail of a website since P2L Hammertime.
There, i said it...
Just my view on the situation