We are preparing to deploy WordPress for internal use. We would like to be able to have Apache handle the actual user authentication with our Active Directory server, passing the username to WordPress, which can be done using the HTTP Authentication Plugin.
Once we have the user authenticated, we would like WordPress to be able to retrieve the necessary user info from Active Directory; things like user's full name, email address, and groups, which could be used elsewhere (e.g. use the e-mail address with Subscribe2 plugin for topic notifications). I have not seen any way to get this second piece accomplished. Every LDAP or Active Directory plugin that I can find expects to do the actual authentication (and thus would make the user log in again).
If you are familiar with Foswiki, this is what is accomplished by using their LdapContrib plugin with the LdapApacheLogin manager. By doing this, I can create a more unified experience for the user across our applications.