Data Mining Addins for Office 2007 Preview Build Now Available!
Download at your pleasure from http://www.microsoft.com/downloads/details.aspx?FamilyID=aa0c2623-b432-4a1f-9a3c-9d64df130a61&DisplayLang=en
Important Excerpts from the download page:
If you have questions about the Data Mining Add-ins, visit the SQL Server Data Mining Forum on MSDN.
Help improve the Data Mining Add-ins by submitting bugs to the Connect Feedback Center.