Isn't the idea of IPv6 that we have plenty of addresses. Thus it wouldn't (read: shouldn't) be hard to get another address bound to your virtual host.

In fact doesn't the whole idea of binding multiple sub-domains to the same IP address (on the same port) kind of go by the wayside when it's free/cheap/not-going-to-blow-up-the-internet to get another IP?

yes you could indeed throw another address at your virtual host. but the website/tool in question won't work with IPv6 addresses as they are not valid in a URL is the point i was trying to make :)