[Hoff]

Sure, NAT and a few more blocks will help. For a while...

With the recent IPv4 address burn rate — the allocation rate the last remaining addresses block were issued — reclaiming a half-dozen /8 blocks would be a rearguard action at most, and an effort and a hassle that would detract from IPv6.

For data, select the column with the IANA date sort here:

http://en.wikipedia.org/wiki/List_of_assigned_/8_IPv4_addres...

and then consider how long a few more added /8 blocks would really last. By my count, fourteen /8 blocks since 2009. And the rate that network-connected devices are arriving isn't slowing.