I run a handful of servers on my home network, most of them connected to the internet somehow. All of my servers however are running in a dualstack IPv6 configuration. One thing that I've found to have changed significantly in Windows Vista is their IPv6 support, which is now complete. Vista itself takes advantage of some of the things IPv6 gives away for free, like neighbour discovery etc.
I've been running IPv6 on my network for about four years now and get my upstream connectivity through a tunnel to SixXs. However! After I got Vista, I suddenly couldn't connect to my Linux servers using the free SSH client, Putty. I recieved at "gethostbyname(): unknown error." message when trying to connect to any IPv6 hostname. For some reason, the internal checks in Putty aren't detecting the newer getaddrinfo() functions that actually support IPv6. I've sent a mail to the Putty team letting them know about the problem, but if there is a C/C++ guru out there who feels like helping out, I'm sure it would be appreciated. The source code for Putty is available from their website, either from SVN or as a zip file.
Oh - and if you do succeed in getting it to work, feel free to send me the patch so I can get my one working too :-)