> Without touching any of that (i.e. configuration), can I talk to IPv6 hosts out there? I'm guessing the answer to this question is probably no.
Yeah. Nobody in IPv4 can talk to you unless you have a IPv4 address. In my case I will still use the IPv4 NAT firewall for that.
But if your running commercial services then you can use a IPv4 compatible IPv6 address.
Most commercial routers besides home consumer kits have been IPv6 for a long time now. Probably most stuff sold to businesses since 2005 or so has IPv6 support. Most corporations are going to have IPv6 aware devices on their network right now. My Android phone supports IPv6 access points.
It's going to be a security issue for a lot of networks... if I use IPv6 I can bypass most restrictions in most networks. Just because your not using IPv6 on your network, doesn't mean that somebody else isn't. :P
I'd say that most corporate networks deployed in 2006 or so is probably IPv6 ready now... or nearly so. They just have to turn it on.
There are enough reasons to use IPv6 besides just the bigger IP space that people are going to look back and say "WTF didn't we do this earlier?"