I have completed a first version of a projection tool that users can use to change the projection of the feature classes in a file geodatabase. Te Add-In is called Reproject. Once loaded, enter or browse to the File Geodatabase that contains the layer to reproject. Next use the pulldown to select the projection. I created the from from this web page....http://help.arcgis.com/en/sdk/10.0/arcobjects_net/componenthelp/index.html#/esriSRProjCSType_Constan...
If you want more added, let me know. After you select the projection, click the Ok button. The only issue with the program is that the newly projected layers were in the 2 feature datasets are now located outside of them.
If you have any questions or problems, let me know.
