These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
In this movie, Heywood Floyd has a much more down-to-earth and blue-collar personality than his officious, patrician portrayal in 2001.
2010 gives us the explanation in the novel as to why Hal went crazy.
Hilarious in Hindsight: Dave Bowman's widow is seen wearing an off-the-shoulder Flashdance-style T-shirt. These actually came back into fashion in the real 2010.
Dr. Floyd's son has a poster of the Olympics in his bedroom reading "Beijing '08" at the bottom. For added flavor, keep in mind that this film was made in 1984, and that the IOC wouldn't declare Beijing host of the 2008 games until... 2001.
Memetic Mutation: ALL THESE WORLDS ARE YOURS EXCEPT EUROPA. ATTEMPT NO LANDINGS THERE. USE THEM TOGETHER, USE THEM IN PEACE.
"You see, something's going to happen." "What?" "Something WONDERFUL."
Humorous variations on the title of the film were used quite a lot as newspaper headlines in the year of 2010.
Surprisingly Improved Sequel: Some feel 2001 was a great artistic achievement, but even some of its fans admit that it can be ponderously-paced at times with wooden characters and a lot of Scenery Porn. 2010 was a better movie for the masses (and some scifi fans) in that it was much less artistic and more accessible.