If you are using Feeds to migrate site content, one of the stumbling blocks will be preserving content ownership.
This code is taken from a hypothetical feeds_usermapper module that provides the option to sync up node ownership on the basis of identical usernames. (Pulled from User Inheritance Issue on D.O)
Bio in Brief: I spend a lot of time thinking about how to build collaboration tools in Drupal. Before that I noodled about with Java looking at long-term data preservation and geospatial data discovery.