Hi there,
1. No, geodatabase replication from an ArcGIS 10 GDB to an ArcGIS 9.3 GDB is not a supported workflow. For all replication types, the child replica geodatabase must be the same geodatabase release as or a later release than the parent replica geodatabase.
Replication and geodatabase releases
2. Yes, we do support backwards compatibility to transfer data and schema from an ArcGIS 10 GDB to an ArcGIS 9.3 GDB with the XML export/import tools. However, new objects that only exist in ArcGIS 10 GDBs will not be imported or may cause a problem during the import to an ArcGIS 9.3 GDB.
Hope this helps,
So essentially people who have put replication in place now have to wait until all the child agencies upgrade to ArcGIS 10 before the parent group can upgrade? We do not want to stay at 9.3 to be the last to upgrade when we are the parent. It seems a little backwards to me. I could understand if the parent had to be the most current version but not the way it is. This really causes a problem for groups wanting to move to 10. I don't know why we bothered with replication since if we want to move forward we need to move anything we replicated back to an export/import routine and abandon replication altogether.