What do you do?
Same as anybody else faced with dwindling supplies of a finite resource: Pay more for it, go bust, or both. Plus, plenty of ISPs already have limited IPv4 address space. Some of them own their own addresses, some rent address pool access from others. It's one of the reasons DHCP was invented.
Massive IPv6 adoption will only happen when the big players, like Google, Yahoo, Facebook and the rest, go to a primarily IPv6 service. Until then, why should Joe Public give a shit about something geeky and technical like TCP/IP?