For example: all the plugin developers could discusses pricing, and security of plugins.
This could be used for any sensitive types of discussions, and it saves a stack of private messaging. I don't know if GForum has this type of feature in it already, if it does it should be easy to set up on here if this is acceptable by others, and GT.
The private area would simply be invisible to non-members.
This may not be well received, but it is something I use on my forum for my editors, and it saves everyone a lot of posting!