I have been working on a 2.0-compatible version of the ee-ldap-extension hosted at google code. I posted my changes there but haven’t heard back from the developers. I could really use some feedback on the approach as I haven’t worked on EE before. Does this look like a good start?
Add a user to the “non-ldap users” in settings before enabling this extension, so you can still log in to the CP if there is an issue with the implementation or with your LDAP settings.