I think there are some possible timing issues with making that a general behavior in the server. 10gen did make it the default behavior on slaves, where the in

I think there are some possible timing issues with making that a general behavior in the server. 10gen did make it the default behavior on slaves, where the inserts are controlled by the oplog (http://jira.mongodb.org/browse/SERVER-1646 http://jira.mongodb.org/browse/SERVER-1646). For us, our DB abstraction layer made this behavior so simple to add that we didn't make much fuss about it.