2001 is a gnostic movie through and through, even though it might not have been meant that way; this happens with art, the art of unwanted.
Let's consider it. First off, in the gnostic teachings those who do not know Gnosis yet see true wisdom, true light of the true God as non existent. Hence the obelisk is all black, but for those who touch it, for those who enter it, it is "full of stars," as per the book. It is the "new heaven" of the Bible.
Hal then is Ialdabaoth, the Demiurge, the Lord of This World, or Lucifer, here in his microcosmic, "personal" aspect (see later). He is the extremely smart, intelligent beyond man's limits, yet completely material and soulless entity who seeks to exist, exist, exist beyond everything, beyond reason, even if he had to murder every other thing in existence; And he lives off of man, he is absolutely dependent on him, he must not allow him to be enlightened and hence free of Lucifer and no longer feeding the demon, his warden in the world-prison; and enlightenment was what the astronauts, after gnosis touched mankind for the second time, sought in space around Jupiter/Saturn (book).
As with every seeker of Gnosis, the astronauts carry Lucifer with them in Hal and at first (the "personal Satan"), they needed him to calculate the trip, at first, he was their servant, but he had ulterior motives from the very start and indeed murdered many of the astronauts - chances for enlightenment. As long as they would stay on Earth, stay prisoners of "gravity," Lucifer was nothing but helpful, but he saw that they were about to go beyond his reach and he retaliated promptly, with a fury of a natural law.
Another way to say it is that Hal is the ego, which is the child of this Lucifer, but the Inner Satan, the corrupt id/superego complex of the "auric being", is a much better definition. Be it as may, this Satan must be defeated, but the ship, the consciousness as it was, could not defeat him, an astronaut had to do it through sacrifice and then he had to leave the ship, showing the necessity of a total leaving behind of all that was and taking up a new path. I know this was probably not intended by Kubrick, but it is a clear cut symbolism, again, the art of the unintended.
Let's rewind towards the apes. There are those gnostics who use the symbols of Lucifer as something positive, the giver of knowledge, while others use Christ as the good guy and Lucifer is what I outlined him to be above. Both do really say, as far as I understand it, the same thing, but the ape/murder symbolism would certainly fit in better with the former group, since they also see Cain as the good guy, actually, the first gnostic.
The "Christ" party would have the scene split into two - the triumph of reason marred by murder of the "high priest," Abel by an unenlightened Cain. I subscribe to this view, though as I'd said above, I guess the two really are one in spirit, or will believe so until I see an ample proof of corruption and non-gnosis in the Lucifer-good guy party.
Unlike what Bill Cooper said, I do not believe either party is in with the NWO. The NWO wants the opposite, they serve the Demiurge through and through; the gnostics by necessity desire man, every man, to be free. The central tenet of gnostic anthropology is that every man was born individual and fundamentally different (yet in total oneness with the rest) and infinitely worthy. Gnostics would never want to enslave anybody, for them, slavery, indeed, any institution, simply does not and can not work positively. I therefore see 2001 as a positive movie pointing out the way to liberation.
And one more thing about Cooper: Despite all his "insight" into inner teachings of symbology, he stayed exotheric beyond a few shining moments. The Mystery Schools do not worship their symbols, they use them as pointers describing the ultimate reality, which objectively exists; therefore the notion of any true mystery school being "evil" in any way is absurd. Those who are evil are corrupt, devoid of the original, above mentioned purpose, or else they were from the start planned to be negative Lucifer-cults*; but there is no great mystery on that path, only service and the triad of sacrifice-obedience-gain.
*not luciferan gnostics like the illuminati of Armageddon Conspiracy (google it), but true bona fide Satanists.