Yes, it does depend on whether your upstream provider, i.e. ISP supports IPv6. DNS root servers supports IPv6 and most domain name services should support IPv6

Yes, it does depend on whether your upstream provider, i.e. ISP supports IPv6. DNS root servers supports IPv6 and most domain name services should support IPv6 by now. There is no NAT in IPv6. The address that you get should be globally routable, Unless of course your ISP have any IP filters in place. In the end it will depend on how your ISP allocates IP addresses to you. Initially, the main issue was non-IPv6 capable CPE devices like your cheapo ADSL modem. The way around this was via Teredo tunneling, tunneling on IPv6 packets within IPv4 UDP packets. Windows Vista and above supports IPv6 pretty well out of the box including Teredo tunnelling out of the box. Most BSD flavours are alright via the KAME project... not too sure about Darwin though. Anyway, it's been awhile since I've worked in the IPv6 area so god knows what else they've come up with.