Greg Kelly has written a nice overview of the various ways PeopleSoft can leverage LDAP - including dynamic role creation.
I would like to add two additional points to his post in relation to PeopleSoft and OVD.
1 - While we have not yet done "official" certification of OVD with PeopleSoft, we have customers using this configuration and we have tested this combination internally with PeopleSoft support.
2 - For those who have access to Oracle Open World OnDemand (or bought the CDs) - check out our co-presentation with the State of Delaware on how they use OVD to expose PeopleSoft data using PeopleSoft's Web Service capabilities.