Hi Jim,
Good questions. Thanks for asking as I'm sure several others are wondering the same.
Moving repos between organizations is done through the UI in a few clicks, IIRC. The person needs to be able to create repos in the new organization. Looks simple.
Developer repos will need to be updated with a new remote URL *if* they reference the official repo in some way; however, their personal forks will not move. I can send out an email explaining how to accomplish this.
Deployers and others that use the binaries from Maven will not be affected.
There might be additional unforseen issues, though unlikely. Thus, the action of moving one repo to evaluate impact.
Does this make sense?
--bjagg