So, I did a few installs for the Vista launch hullabaloo, aside from the fact that it's annoying that you can't use an upgrade disk unless Windows actually boots, I was able to work with Vista without much incident, until I tried to install NAV.
Basically the current CD copies of Norton products out there won't recognize Vista as a valid installation platform. The setup will state that it requires Windows XP and exit. In order to get around this you'll need to download the newer trial version of your product and input your full key during the installation process.
Download the trial from here: http://nct.symantecstore.com/0001/
You'll need to give it a valid email address to get the full download link, I gave it a junk email address as Symantec will be spamming whatever email you feed to it. Still, it works none the less.