All curOp entries now have an "effectiveUsers" section, which is an array of usernames of the users whose permissions apply to the op. Additionally, curOp entries from shards include a "userImpersonators" section, which is a list (usually just one item with the __system user) of users that are impersonating the identity of the effective user.
It would be useful to have authentication information for each operation in the results of currentOp. In particular, the database and user.
- Release notes