Most people already know that In his 1984 book "Neuromancer" he basically predicted the future importance and uses of the internet and the existence of portable devices to access it (It was he that coined the term Cyberspace). he also emphasised virtual reality, which back then was somewhat of a niche fad but even now is about to become more mainstream with the imminent release of Occulus Rift, off the back of which there is already a series of similar devices being leaked/advertised.
Agreed. But for me the most visionary prediction in the trilogy is that corporations have basically taken over the reign of the world. Which nowadays is terribly spot on, unfortunately.