Originally posted by: fleshconsumed
Read the book - it explains a lot and its sequel 2010. That guy (the one who survived, sorry don't remember his name) got abducted and later reborn as a new entity without physical form, consisting of a pure energy.
Do NOT read the book.
This is perhaps the only instance where the movie is better than the book -- and it's precisely because Kubrick was smart enough to realize that the ending should not be explained, but left to the viewer to speculate about. Our encounter with the monolith at the end of the movie is supposed to be as unfathomable to us as it must have been to the pre-humans at the beginning of the movie. What will the consequences of this second encounter be? Are the monoliths "merely" devices built and left by aliens, or are they evolutionary signposts of the "gods", or what else? Everyone who sees the movie gets to form their own "ending".
The movie was based on a short story by Clarke. Too bad he decided he had to write the book, and try to explain it all as some sort of initiation ritual into the community of intelligent beings. And even worse that he decided to write sequel after sequel that only detracted from the original idea (as he also did with horrible results to his Rendeverous with Rama).
It is too bad that the special effects at the time the movie was made are now so outdated, but get past that and it's still one of the very best (if not the very best) science fiction movies ever made.