I'm sorry if you're unfortunate enough to be running Plesk, but I do applaud them for adding IPv6 support.
http://drdobbs.com/high-performance-computing/229400369?cid=nl_ddjupdate_2011-04-05_html
i use cpanel and plesk.
cpanel on linux
plesk on windows
both servers are configured with ipv6, and it doesnt matter if they dont have an special area on their pannel, you can configure it via ssh or control panel.
so, im great with both =)
I think the post is referring to the fact that you can access Plesk via IPv6 (instead of using 1.2.3.4 you can use 2001:db8:1234:5678::1)