the challenge: nbm:populate-repository goal is tuned on creating both individual nbm project metadata and also the per-cluster aggregator metadata projects.
the stuff from update center shall be created just the individual nbm project metadata but shall not be included in the cluster metadata (as people assembling the platform applications will generally use the cluster projects as dependencies and shall not by default end up with stuff from stable update center)
this might require some minor tuning in the nbm:populate-repository goal to skip cluster metadata generation.

Then we would invoke the nbm:populate-repository goal twice, once for the standard distribution and once for other modules (in cluster file structure) from stable update center.

How about rather creating an FAQ entry for the users who want to import any NetBeans module to a repository of their choice (a local repo, or a company repo).

(In reply to comment #2)
> How about rather creating an FAQ entry for the users who want to import any
> NetBeans module to a repository of their choice

This seems better to me. We cannot predict what modules people might want to use from Maven, and I would expect the great majority of people to use only modules from the standard distribution.

(In reply to comment #3)
> This seems better to me. We cannot predict what modules people might want to
> use from Maven, and I would expect the great majority of people to use only
> modules from the standard distribution.

Agree with Jesse, so the question is who is going to create such FAQ ?