I'm trying to justify moving some organizations over to the Google Apps system, but something that we need is the ability for forums style discussions. Google Groups *might* be able to fill that role, except that the inability to create discussion subgroups (as in multiple categories of discussion) without creating and managing individual Groups for every category your organization wants to be able to have. (including user subscriptions to each group).

This is further complicated with a lack of Google Groups and Google Apps integration. I can't even register with a 3rd party forum system, and link with iframes on the Sites portion of Apps.

Does anyone have any insight on what the hangup is for things like this, and is Google Groups simply the redheaded step child of the family of services Google provides?

It's baffling that I can have shared calendars, shared documents, shared community websites, group email, but no way to communicate as a group with open discussion.

Now sure if google groups will ever become anything like a forum solution. i don't believe it will and i don't know if google will ever offer one but there are open source forum softwares you can use.

Google Groups doesn't seem to be prioritized anymore by Google.

Maybe Google App Engine for your own domain could be a solution?
http://appgallery.appspot.com/results?q=forum

Yeah, I saw one person working on a forum app on appspot. I doubt I'll be able to muddle my way through writing my own though.

as far as other free solutions, I know they're out there but I was hoping to make the move as seamless as possible for the users, which means single registration.

it's just too bad that Groups is not (apparently) getting much dev love, and I don't recall a google purchase of something that might be better (like google sites vs google pages)