My suggestion for Forum areas:
- end-users (newcomers, power users)
- community (community members, contributors, council)
- developers
- builders (vendors, hobbyist) [new with MeeGo]

I differentiate only these 4 on the highest level due to their different interest in coming to MeeGo:
E: use, get answers (Q&A, FAQ), learn
C: discuss, contribute
D: develop, distribute
B: build MeeGo devices

I think the high noise ratio on TMO is due to the fact, that there is no focused attempt to serve end-users for their typical need. TMO itself was a step to provide a place for community besides developers. My opinion is that there is no need to drastically change what has evolved previously - just add end-user focus and builder focus.

I agree with starting from scratch and starting with high-level grouping only.

I think spinoffs will happen later (e.g. end-user Q&A could be better in structured form instead of forum, community functions like brainstorm etc.) and sub-forums can spawn when there is need.