Apparently Vint Cerf is claiming that the sky is falling - saying that Internet Service Providers urgently need to roll out IPv6 to allow us to use more than the 2^32 (4 billion-ish) addresses that IPv4 (what we're using just now) allows...
The BBC tells us that IPv4 is projected to run out in 2010 or so.
Whilst *eventually* IPv4 addresses will run out, I think we're a lot further off having to use IPv6 than the Beeb suggests. Remember, we're talking about upgrades and reconfiguring almost every router on the planet here!
There are millions of IP addresses wasted out there - from the days of a few big companies having class A and B networks, they allowed real live IP addresses to be assigned to desktop computers. (The computer I am at right now has a publically routeable IP address, of course, the corporate firewall prevents it from being of any use to me!) If these address ranges were reclaimed, we'd have millions of addresses to spare! Who needs a routeable IP address for their toaster anyway?