1) Just re-assign multicast!
Silly, and amusing, but possible. :)
2) Hey, they don't appear to be using those addresses, let's take those!
Very valid. There is a /8 assigned to packet radio operation... Not common, and not often connected to the actual Internet anymore. Oh, and not paid for at all.
3) Double/Triple-NAT is good enough for me and everyone else!
I am with you here. Especially that nasty NAT abomination in 2Wire routers "DMZ Plus Mode."
4) Let's give out one IP address to everyone and we'll be set for awhile!
Never heard that one...
5) Let's make a new protocol!
That is how IPv6 came about. But then again, look how it turned out...
6) IPv6 addresses are too big to remember!
Very valid point. Especially when your ISP DNS craps out and you can actually remember 4.2.2.2 or 8.8.8.8 or 198.6.1.1 without the Internet to look it up.
7) You just need to sell it better!
Huh?