Hi, Marco
yes, there is 'Account Policy Plugin' updating the attribute 'lastLoginTime' (http://directory.fedoraproject.org/wiki/Account_Policy_Design). I haven't tested how it works with replication, i'd be interested to know the results...
Up to the version 1.2.10rc1 there was a bug in the case when the PAM pass-through plugin was used (https://bugzilla.redhat.com/show_bug.cgi?id=712294).