Well, after finally buying 2001: A Space Odyssey, the novel, while in Chicago on Friday, I just finished the book this afternoon. Besides the fact that I am more confused when I was when I watched the movie, I also would like to point out how, since the year is now 1999, and Section II of the novel takes place in 1999, just how close Arthur C. Clarke actually was to guessing at this year. Also, some stuff that was way off too 
1) Video Phones: Though everyone has one in the movie/novel, they still exist now
2) Space Planes: Though they were commercial in the movie/novel, they still exist today, in the form of the space shuttle.
3) Computer's with voice recognition: Though HAL could actually recognize exactly what you said, we still have computers today that respond to sound.
4) Life on other planets: Though 2001's lifeform, The Monolith (TMA-1), was much more profound, we still have a glimpse of life from Mars, in the form of asteroid ALH84001
5) Internationally owned space stations: Though ours is still under construction and looks nothing like the movie/novel's, 2001's Space Station One was built to cater to the needs of Americans, Russians, Chinese, French, German, and Spanish.
6) China's Nuclear Capability: In the novel, China is said to be selling aged 50 nuclear warheads for $200,000, and some believed that China was doing this for money and for the fact that China might have built a super weapon. Well, though China itself isn't technically selling nukes, there is still a black market for them.
Now, some major differences:
1) Colonies: First off, we don't have Clavius Base. Colonization of the moon is still a long way off. We also do not have colonies on Mars either.
2) Fusion powered space ships: USS Discovery is powered by massive nuclear reactors. Even though we have some satellites with nuclear power, we don't have any real space craft with nuclear capabilty
3) HAL 9000: Though our computers are advancing at an astronomical rate, we still don't have a Heuristically programmed ALgorithmically Programmed (that is where the letters HAL actually came from, NOT IBM) 9000 series computer.
4) Cryostasis: The only logical way to get humans to other planets would by cryologically freezing them. Though we are still tinkering with the idea now adays, it's still years off.
5) Pan Am: Well, obviously Pan Am ain't around anymore 
6) U.S.S.R.: Unfortunatly, the Cold War is over, and there is no more 'Russian Bloc'. Unfortunatly, this really destroys a lot of the plot behind 2010: Odyssey 2.
7) Moons of Saturn: As you may know, the novel version of 2001 has USS Discovery going to Saturn instead of Jupiter, which also screws up 2010 again! Anyway, Clarke's list of moons of Saturn is a bit short. The current list has around 18 moons, though Clarke claimed there were roughly only 10 or so
8) Construction of USS Discovery: USS Discovery was supposed to be built in space, though right now, it would be extremely tough to build an object of that size in space, especially with how slow it takes the US Space Shuttles to ferry pre-built parts up to orbit.
9) Satellites: The number of extraterrestrial satellites sent by Earth is mugh larger then the number sent out in reality. One satellite includes a listening post, Deep Space Monitor 79, a space-borne version of SETI, a Mars orbiter called M 15, and Artifical Comet 5, which has an orbit that goes beyond Pluto (eek!)
Anyone else have anything to add to this?
------------------
"The things hollow--it goes on forever--and--oh my God!--it's full of stars!" -David Bowman's last transmission back to Earth, 2001: A Space Odyssey
[This message has been edited by The359 (edited November 09, 1999).]