How many people are aware of the IPv4 Address Exhaustion problem with the current implementation of the Internet?

XKCD did a pretty interesting bit on who owns which addresses in 2006. At the time, the green bits were "unallocated," that is, not owned by anyone, the rest were assigned to various companies or registrars.

I'll note again, that was a rough estimate in 2006. Rough estimates in 2010 (http://ipv6.he.net/statistics/) (ipv6.he.net) put the time until we literally run out of unassigned IPv4 addresses to give to people at less than a year (~200 days).

ISPs (like AT&T) are making efforts to rearrange their IPv4 addresses to free up space, segmenting their internal networks from their external networks (and thus freeing up potentially unused internal addresses with externally routable IP addresses), but not everyone is terribly cooperative, and not everyone has a flexible enough network design to allow for this.

Thus, in the near future, ISPs are going to have to switch over to an almost entirely "new" Internet, running the IPv6 protocol, which contains a much more expansive address space. Certain services won't be available on IPv6 (for instance, the idkfa server has no IPv6 support), or certain programs will not work without considerable updates to allow for the new addressing schemes. Modern operating systems (Windows, Mac OS X, Linux) already support IPv6, but that doesn't mean their programs will, nor will they be bug-free.

Just saying: next few years on the Internet should be interesting.