With upcoming NetScaler release „Dara“ there will be no more excuses to not run a pure (or mixed) IPv6 enterprise network without headaches regarding Internet uplink being IPv4.
NetScaler has support for NAT64 since quite some time already. What’s coming next is DNS64, i.e. NetScaler will add the configured NAT64 prefix to A records running through a DNS LB VServer. By doing so, nobody depends on AAAA records available.
As an abstract statement: with NAT64, DNS64 and NAT46 there is no reason not to deploy and run a pure IPv6 enterprise network from LAN to DMZ anymore.