I recently bought Aldous Huxley's Brave New World Revisited. It's a collection of essays written almost 30 years after he published Brave New World. He looks at the predictions he made back in 1932 and compares how society has changed in the intervening years.
Also added more books to my wish list:
John Brunner: The Jagged Orbit
John Brunner: The Sheep Look Up
John Brunner: The Shockwave Rider
John Brunner: Stand on Zanzibar
Harry Harrison: Make Room! Make Room!
Gabriel Garcia Marquez: One Hundred Years of Solitude
Tom Wolfe: The Electric Kool-Aid Acid Test