A new version of the script that moves domino groups to AD was released.
This script will move Domino Groups to Active Directory while preserving SMTP Addresses by creating contacts in AD for these users. By default Move-DominoGroupToAD will drop SMTP addresses if they do not already exist in AD.
Read more at source: http://blogs.technet.com/collabtools/archive/2008/09/05/updated-script-for-moving-domino-groups-containing-smtp-addresses.aspx