In the last days I migrated all my internal services to IPv6.
All my jails have an IPv4 and an IPv6 address now. All Apaches (I have one for my picture gallery, one for webmail, and one for internal management) now listen on the internal IPv6 address too. Squid is updated from 2.x to 3.1 (the most recent version in the Ports Collection) and I added some IPv6 ACLs. The internal Postfix is configured to handle IPv6 too (it is delivering everything via an authenticated and encrypted channel to a machine with a static IPv4 address for final delivery). My MySQL does not need an IPv6 address, as it is only listening to requests via IPC (the socket is hardlinked between jails). All ssh daemons are configured to listen to IPv6 too. The IMAP and CUPS server was picking the new IPv6 addresses automatically. I also updated Samba to handle IPv6, but due to lack of a Windows machine which prefers IPv6 over IPv4 for CIFS access (at least I think my Windows XP netbook only tries IPv4 connections) I can not really test this.
Only my Wii is a little bit behind, and I have not checked if my Sony-TV will DTRT (but for this I first have to get some time to have a look if I have to update my DD-WRT firmware on the little WLAN-router which is “extending the cable” from the TV to the internal network, and I have to look how to configure IPv6 with DD-WRT).