Hi. I wanted to let everyone know that this was release this past weekend on Snowcovered. The full release includes the ability to import all core and extended fields, use different files with existing import definitions, export module to export all fields and allow you to choose the delimiter etc... The module also includes a 'Purge all portal users' feature to delete all portal users except administrators. This can be helpful if you ware wanting to test importing users several times and then clean out the portal from these users.
-Chad