OP says he hasn't received any offers on this domain in a long time?? Because it wasn't for sale?? IMO, whether it was listed for sale or not, if some major players wanted to get their hands on this, you would have heard from them in some manner or another. I agree with some of the people who put forth the idea that most of the major players already have social networking platforms, so BIG money demand is probably lower than most think. Startups won't have the funding and it's unlikely that VCs are going to pour money into social networking startups when the established major sites like Facebook and Myspace can't even monetize their traffic. If anything, I think we'll start to see a shift towards niche social networking sites, whose sole purpose is to funnel targeted traffic to a company's main product line... I.E. Ford starts a car-related social networking site as a marketing campaign to drive car sales. Maybe, maybe not. I also think that the social networking craze is a fad that has grown largely popular by the fact that more and more people were being introduced to the Internet in mass and it only made sense that they would invariably pool somewhere... I think people will get bored of it after awhile and start to branch out and explore more of the Internet and find more specialized, niche environments in which to dwell. But what do I know?
Anyway, I'd say low - mid $xxx,xxx