IPv6 is vary useful for peer to peer communication such as torrents and skype. My roommate and I sit behind NAT and rather than choosing a single PC that get's fast torrent downloads IPv6 can gradually increase the number of peers other PC's can see. Even better the speed scales up as adoption increases. Also, when you want remote into a more than one home PC you can do so directly with IPv6, you don't need to pick a single host and then remote into other machines on your network.

The only downside is you need better firewalls.