I think the article made it clear that IPv4 is running out of addresses DESPITE using NAT heavily.
As far as reclaiming large A blocks is concerned, I read somewhere that we are exhausting addresses equivalent to an A-class block in 5 weeks. Easy to see that we are going to need a long-term solution anyhow.
I linked this elsewhere, but you can see here: http://twitter.com/ipv4countdown from the history how fast they are being used up - a million every couple of days, or thereabouts.
As far as reclaiming large A blocks is concerned, I read somewhere that we are exhausting addresses equivalent to an A-class block in 5 weeks. Easy to see that we are going to need a long-term solution anyhow.