In hindsight, we reached peak IPv4 two years ago. The good news is that IPv6 is doing very well—but not nearly well enough. Is the IPv6 glass 1 percent full or 99 percent empty?
“Hi, I’d like to sign up for Internet service at my new apartment.”
“That’s great! We have the highest speeds at the best prices, you won’t be disappointed. But unfortunately, last week Europe ran out of IPv4 addresses. We still have plenty of IPv6, though.”
“IPv6? So I can use that to visit all my favorite websites, use IM and VoIP, download podcasts, and watch videos?”
“Well…”
Luckily, I escaped this conversation when recently signing up for an Internet connection. But if I move again next year or even the year after, I could end up with a faster Internet connection that is less functional, because it will no longer let me connect to every other Internet user. All because we ran out of numbers, which don’t even cost anything. Sadly, not having them will cost us a lot of time, money, and effort as some cling to IPv4 and others adopt IPv6—by choice or otherwise—over the next few years.
Where we stand
First, let’s look at IPv4. Five Regional Internet Registries (RIRs) give out IP addresses in different parts of the world. APNIC (Asia, the Pacific, and Australia) ran out in April of 2011, and this past September the RIPE NCC (Europe, the Middle East, and the former Soviet Union) did the same. As a result, the number of IPv4 addresses given out this year is about a third of what it was in 2010: only 80 million.

Full Story: IPv6 takes one step forward, IPv4 two steps back in 2012 | Ars Technica.