Your ISP almost certainly doesn't support IPV6 yet. Only a handful do.
Even so, you can (and will) participate in the test, either voluntarily or involuntarily.
Participating sites will turn-on IPV6 support for a day. They will support BOTH IPV4 and IPV6 connections.
You can test whether you can reach these sites via IPV6 if your ISP supports IPV6 and your computer and router support IPV6, or if you use a "tunnel broker" to tunnel traffic over your ISP's IPV4-only connection.
You WILL test whether you can reach these sites via IPV4 if your computer, router, or ISP support IPV4 only.
There are apparently some potential issues revolving around DNS for IPV4-only users. Initial access to sites could be significantly delayed by the DNS lookup.
I think the test is really more for the latter than for the former. It's to find out "will turning on IPV6 sites break IPV4 access"?
Not sure how important DHCPV6 is. My understanding is that IPV6 really doesn't have a need for DHCP, since there is no NAT (no need for NAT, given the large address space), every IPV6 device has a default globally-unique address, and so is self-configuring. DHCPV6 exists primarily to allow network administrators control over addressing within their organization.
http://en.wikipedia.org/wiki/DHCPv6