I just published the Demonstrating an IPv6-only Environment extension for the IPv6 Test Lab in the TechNet Wiki.
With this extension, you reconfigure DC1, the native IPv6 router for the Corpnet and Corpnet2 subnets, to stop advertising address prefixes and act as a DHCPv6 server to assign IPv6 addresses and the IPv6 address of a DNS server (DC1). Then, you disable IPv4 on all interfaces on the Contoso intranet and test Active Directory, Web, and file sharing to show that it works the same as the Base Configuration test lab (which is an IPv4-only environment). You can snapshot this environment and use it to test whether applications will work properly in an IPv6-only environment.
If you have an idea for an extension that adds something new and interesting to a test lab, by all means, write it up and publish it in the TechNet Wiki. Here is a blog post to get you started.
Joe DaviesPrincipal WriterWindows Server Information Experience