Currently, Import Contacts throws a fatal error when the actual Import starts (after submit of step 3):
Fatal error: require_once() [function.require]: Failed opening required 'CRM/Contact/DAO/Individual.php' (include_path='.:/Users/dgg/htdocs/drupal/sites/all/modules/civicrm/:/Users/dgg/htdocs/drupal/sites/all/modules/civicrm//packages:.:') in /Users/dgg/svn/trunk/api/utils.php on line 1330
(I think things are stable enough schema wise to get this functionality working again )
I've attached the test import file I was using. I did not "map" the custom field columns. Also didn't map the "ID" column (which would be for updates only). I had one matching contact already in the DB and selected "Update" for my Duplicate Handling option.