A question which kept popping up is whether certificates should have attribute information in them. But attribute certificates are useful enough in some cases that they won't go away. On the other hand , Microsoft took the position that the certificate should have nothing but the public key. You then look up the name in a directory using the key as the index. Kind of extreme.
Directories are still a major concern.
They are an essential part of access management systems. Just about everyone there is using or building some kind of metadirectory. Nobody even thinks about asking HR to use the directory as a repository for authoritative data. This was their experience setting up an LDAP-enabled university directory system. It was very similar to our efforts, right down to the difficulty dealing with the registrar to get data.