For every techno geek like us, there are many more people with 0 devices that require an IP. OP was comparing number of IPs in IPv4 with number of people on earth. Since we are only just now starting to run out of IPv4 addresses (the last big blocks were assigned recently, but there are still gaps and sparsely filled blocks), it seems safe to say that on average the number of IP enabled devices is lower than the number of people. That won't last long though.
As technology filters down to the third world, and (assuming there isn't some massive device convergence that reduces demand for IPs in the first world) the ratio of devices to people will rapidly become skewed. It's a lot easier to pump out cell-phones than babies after all :D
