Well, checking the #SER link in the banner, someone took down the CGI::IRC page so we can't immediately got the IRC chatroom in the browser from this site. The #SER chatroom is still there on irc.psigenix.net, and before I joined it to check, it did have exactly 4 current members so nice guess AJ!
In terms of online socialisation trends, I've noticed Skype has been up in popularity. Not just for voice conversations (though there's that), but it has these features for text chatrooms where once you've "joined" the chatroom, you can log out, and log back in again and get updated on all the conversation that happened while you were gone. Just remember the "/alertsoff" command so you stop getting annoying signals everytime someone makes a message in the chatroom.
I've also found Steam (of course) great for online socilisiation, I actually met up with an MCer a while back on TF2. We still have a Sonic Eats Rings group on Steam actually:
http://steamcommunity.com/groups/soniceatsrings So maybe we should arrange something, since the socialisation aspects of Steam have been improved. If anyone wants an invitation, just ask (with Steam username of course)
Other than that, yeah, there are a plethora of other online socialisation methods, but most of them are more ad-hoc (Twitter, Tumblr) where you pick and choose who you want to talk to and creating groups is a lot harder. The advantage of talking on SER is that I kind know who I'm speaking to. Wheras if I make a Tweet on twitter, I'm not sure if I'm being listened to by Furries or Irish Game Developers or total strangers (the answer most likely being all of the above).