A number of formerly active forum members now hang out in The Board Room. We talk about a lot of things (SBCs, microcontrollers, 3D Printers, Gaming, Slavic Rock, Gardening and more). Feel free to drop by and talk about whatever, really.
There's also a quieter Discord - NTC unofficial that's aimed more at ongoing CHIP related discussion.
There's an official(ish) Internet Relay Chat (IRC) channel at irc.freenode.net called #chipsters. There is a web interface for this but at times this may not work too well as there has been some SPAM on the channel. You can visit the channel without signing in, but to chat, you will need to register, and then identify yourself with NickServ
In addition to going with a browser, you can also use dedicated IRC software to go to Freenode. There are many IRC clients available, both GUI and command line. Examples are IRCII, irssi, weechat and xchat.
There's a facebook group at CHIP Single Board Computer