Sometimes we take for granted that engineers can create new technologies that far surpass anything we may have thought possible just a few years ago.
IEEE 802.11n is a good case in point. I can recall writing about the first WLAN standards a decade ago when a couple of megabits per second was considered a pretty good data rate.
WLAN "deliverables" have gotten progressively better over the years (as one might expect). But who could have guessed it would get to 200 Mb/s? Not me.
But then we didn't know about MIMO, OFDM, beamforming and other technologies at the time.
To get a better idea of just how far we have come, you might want to read our most recent 802.11n tutorial. More information is available at Tutorial on 802.11n PHY layer.