I have read from multiple sources that the GDB toolset (which was available for ArcGIS 9) is not currently available and is not currently in production. I would like to see this extension available for v10. I used the v9 extension on a daily basis and it really helped out with showing the lineages of the several versions we had at one time. I've read several different forums and there are many users out there with the same comments.
This idea has been merged with Release the GDBT for ArcGIS 10.