While I'd admit that we need to evolve past IPv4, the guys behind IPv6 made some serious mistakes when they designed it. They designed a protocol for a "perfect" world and not a real one and have resisted efforts of the business world to get them to change it. One is that 128 bit's is entirely to freaking long for a unique address, heck 64 is too long, but somewhat doable. Next is the way of encoding address's only works for router guys, for everyone else it's not a practical method. Then they try to force you to use IPSEC, something that has broken compatibility depending on how the vender implements it. Products from different venders trying to use IPSEC between them run a 50/50 chance of it just not working. It's so bad that NSA has designed their own HAPIE specification that use's RECIPe (Remote Encryptor Configuration Information Protocol) to enable and setup the tunnels (it's a heavily modified IPSEC implementation). And to final straw is that they refuse to support any implementation of NAPT (what was have in the IPv4 world), which immediately stops many companies from switching over. It's so bad that a Chinese college student went out and built a NAPT66 module for Linux.These guys should refocus themselves towards building a similar model for the future based on IPv6.