Right now we are working on the Auth system for Geeklog 2, details are
here . When we get that stable I do plan on abstracting out just the authentication portion of GL 1.3.x so it can be extended. Just so you know, we do plan to support both LDAP and Microsoft's bastardization of LDAP commonly referred to as Active Directory.
The reason people blame things on previous generations is that there's only one other choice.