Several teams at Microsoft have "Product" sites that include product lines / sub-products in them. A great exampe of this is the ASPNET site which has Dynamic data, MVC, etc all in one place. The forums however do not allow you to segment into sub-forums. That means that readers in such sites may have a lot of noise to deal with. In particular if one subscribes via email it is pretty annoying.

The proposal is to allow site-owners to create sub-forums which could be used for specific products or broad conversations that deserve their own forum.