People who think the beings at the end of the film are robots are
ignoring their resemblance to aliens. People who think they are aliens
are ignoring their resemblance to robots. What if the aliens of Close
Encounters and, especially, 2001 are robots? Of course, for this to be
possible, the robots/aliens must invent time travel, which they do not
appear to have yet invented in A.I. But given an eternity, why wouldn't
they invent it eventually?
It's no accident the ending of A.I. (where the aliens re-create David's
home and observe him) resembles the end of 2001. This suggests that the
aliens in 2001 are descendants of the robots created by man, and these
are the same aliens/robots who trigger the "Dawn of Man," making the
robots created by man, the Creators of homo sapiens.