Are there any question about OpenStreetmap considered on-topic here? If so, what kind of question would be inside the scope?
We have a few existing questions about OSM, which I'd consider all to be on-topic.
I don't know if this is relevant to the discussion now or not, but I just saw that the help forum for OSM looks pretty much like any other StackExchange site. Is this another stackexchange site, or have they copied the design of stack overflow?