I was doing some playing around with a Server 2012 R2 DHCPv6 server today and noticed that Windows 8.1 will automatically pick up an address from DHCPv6. (Windows 7 wouldn't do this without some configuration changes with netsh and some luck.) It will also propagate IPv6 DNS servers automatically
FWIW FYI
Windows 7 dhcpv6 Just Worked(TM) for me. Nothing extra needed to be done.