The LDAP User Component and Plugin is ready for the testing.
Admin need not provide what kind of backend LDAP implementation(e.g. AD or OpenLDAP) the joomla is using.
I tested it for Microsoft AD 2003 and OpenLDAP. And seems work fine for the configuration.
Following are the snapshots of my test configurations.
Microsoft Active Directory 2003
LDAP Configuration
AD User Template Details
User LDAP Plugin
OpenLDAP
LDAP Configuration
OpenLDAP User Template

The code can be downloaded for testing from:
http://code.google.com/p/joomla-ldap-integration/downloads/list
Please report any problems to