It's coming with the new forum. Several options will be available. See here:
https://bitcointalk.org/index.php?topic=523070.0Fancy Authentication
In addition to normal password authentication, the forum should support various kinds of of alternative authentication. At least password auth, email verification, secret questions, OpenID, PGP, OpenVPN (automatic creation of subnets + IP source verification), and Bitcoin address signing should be supported, with multiple allowable credentials for each auth type. Users should have the option of requiring any combination of these auth types. Like "pgp OR (password AND OpenID)". And users should be able to require that changes to some or all auth types as well as the required combination of types not take effect for some configurable number of days. This allows for different types of recovery methods.
