We discussed this a little on the Area 51 proposal. And though Tridion Stack Exchange can definitely take over any Q&A posts, this leaves "Semi-private" discussions without a place to transition to.
I suggest we still have (a few) intelligent, useful, open-ended discussions on the forum that do not fit the Q&A format. User
CMS Info comes to mind. Much of my own participation didn't fit the Q&A format either.
Though programming and consulting have changed, I'd suggest enterprise customers may still be particular about not using Tridion Stack Exchange.
Whatever we and SDL choose, I suspect we'll have one or more of a few results:
- Customers won't miss the forum (except maybe CMS Info)
- Open non-Q&A questions will appear here
- Customers may ask implementation or other questions via other channels such as Support or Linked-In
So IMO "closing" the TridionWorld forum is fine, as long as we have a plan for those discussions or the willingness to say we don't care what happens to them.
Update: TridionWorld forum has definitely dropped. If that's a trend then it doesn't matter what we say about discussions, especially if no one's around.