So I got a response from vmware tech support on this, and the only thing that worked for me was this:

Pause the install process right before phase 2.

Open a console to the appliance, enable SSH

On the appliance, echo "::1 localhost.localdom localhost" >> /etc/hosts

Continue the installer and magically it works. This shouldn't really matter, but it does, so I figured I'd let people see if it fixed their issues.

Their first recommendation was basically most people's problem: forward and reverse DNS should work before you install. But if your DNS is happy and the appliance still hates life, it appears to also care about v6 lookups.