Good news! The Khronos WebGL forums are warming up, and hopefully will become a great place to learn and discuss.
Still, it’s always nice to have alternatives. Just for fun, I’ve created LinkedIn and Facebook fan groups for WebGL; LinkedIn so that when people start hiring WebGLers they’ll have somewhere to look (recruitment being the sole point of LinkedIn as far as I can see) and Facebook because, well, why not? 
Are there any other WebGL groups people should know about?
[Update] James at Khronos points out in the comments that Khronos.org has a job area where companies can post positions for WebGL folks, and they also have a LinkedIn group.
Khronos.org also has a job area where companies can post positions for WebGL folks and Khronos.org has a linkedIn group. The more the merrier!
Keep up the good work on your Learning WebGL site.
James — thanks for the info! I’ve applied to join the Khronos group, and will post about the jobs board.