I modified a passwd shell script which outputs a file with the SHA512 hash, so it is supported to some degree, but may not work for LDAP.
I'm using SSHA512 with my passwords in OpenLDAP, works just fine. You'll want the contrib pw-sha2 module.
--Quanah -- Quanah Gibson-Mount Platform Architect Zimbra, Inc. -------------------- Zimbra :: the leader in open source messaging and collaboration