I don't get 2001

TCM showed Stanley Kubrick's 2001: A Space Odyssey this afternoon. I have to admit that I've never really gotten the end of the movie; the extended dialog-less sequence. My guess is that Kubrick was trying to say something about other civilizations having existed before us (or else, there wouldn't be a monolith), and other civilizations will follow us (after "Dave's" death, there's that idiotic fetus orbiting the earth).

In doing a bit of research, I was surprised to see that Kubrick himself said in an interview that he wasn't going to reveal what he meant by the ending. He apparently wanted to let the viewers reason for themselves what it was all about, and not feel as though they were missing something if they didn't agree with him.

To be honest, though, I think that whole sequence takes away from the rest of the movie, which is a really interesting science-fiction movie about technology gone wrong. If anything, the monolith is a Macguffin. We don't care that the astronauts are going to Jupiter to investigate this monolith; we care that HAL is trying to sabotage the journey. They could be going on any sort of journey.

What do you think the ending of 2001 is all about?