If someone figures out posting to a specific group, I'd love to hear about it. It's one of the more frustrating things I find about facebook. I'd love to have wow-banter with my wow friends, but I really have no interest in spamming wowstuff to my non-wow friends.
I also found that you can, through the app itself, select specific things to publish to the world, which is nice. That way I can decide on a case-by-case basis what gets posted.