Processing Power
-- In the 40 years since 1971 and the advent or Moore's Law (here's a Wikipedia link if you want to read more about this) regarding the theoretical increase of processing power of microprocessors over time, the power of microprocessors has increased by over 1 million times.

Where the microprocessor of 1971 was able to drive a simple calculator -- that cost almost what a netbook computer costs today -- today's microprocessors are much more powerful and enable the products they power to be very intelligent.  Just look at the capabilities of an iPad or smart phone today.  The Apple iPhone 4S and the Siri intelligent agent provide the capabilities the movie "2001 Space Odyssey" nearly human mainframe HAL (including some humorous emulation of HAL).  Of course at the time HAL (by the way one letter further ahead in the alphabet for each of the letters in HAL spells IBM) was viewed as utterly science fiction -- today it's a consumer device that fits in your pocket.

We are not far from cars that drive themselves and manage the fits and starts of traffic.  A number of manufacturers (here is a link to a Wikipedia topic on the subject with videos etc...) are experimenting with the combination of intelligent cruise control (using radar range finding capabilities) combined with internet based traffic data.

As a matter of fact, the average car has numerous intelligent systems using many microprocessors to manage braking, cruise control, fuel injection, climate control, air bags and much more.

The microprocessors that power the average smart phone are more than capable of powering some very intelligent things. Considering the fact that they have built-in communications (cellular, Blue Tooth and WiFi), user interface, storage et al.  Simply add some analog and serial i/o and you have a perfect platform  on which to build some powerfully intelligent things.

One final thought on the subject -- the computers that took Apollo to the moon and back were really nothing more than special purpose calculators.  Even the computers on the space shuttles were pretty much built to just calculate and do specific functions.  The average laptop could have run every system on the space shuttle while streaming the latest episode of "Third Rock from The Moon" without dropping a single frame....