The IPv6 development branch (/playpen/LUSCA_HEAD_ipv6 in subversion) now handles IPv6 HTTP clients. It is still limited to IPv4 servers and other protocols (snmp, icmp, htcp, ftp) are all still IPv4.
But it's a (long overdue) start.
I'll look at next fleshing out IPv6-aware SNMP, ICP and HTCP as they're reasonably easy - I just need to change the socket handling to be IPv4/IPv6 agnostic.
I'll begin merging some of the simple framework changes back to mainline Lusca once I've committed that memory leak fix that I've been discussing.