I hope forums are not dieing out in favour of social networking.
You can't really discuss things with a huge group of like minded people with social networking, just a select few friends.
I have a few friends into computing, tech and games but most are not that interested. Forums are a great place to discuss things with other that (normally) know what they are talking about. Also great source of help and info when having any kind of problems.
I'm not really a fan of social networking as it is at the moment. For discussion I prefer forums, newsgroups (now that's something that's dying out) and IRC, for keeping up with news I use RSS feeds. I have both Facebook and Twitter accounts but rarely use them.