I'd like to make a move method for directory.
We already have a move for Solr in DirectoryFactory, but it seems it belongs at the directory level really.
The default impl can do a copy and delete, but most implementations will be able to optimize to a rename.
Besides the move we do for Solr (to move a replicated index into place), it would also be useful for another feature I'd like to add - the ability to merge an index with moves rather than copies. In some cases, you don't need/want to copy all the files and could just rename/move them.