Re:About the ending--**SPOILER** (Score 0)

I got the impression that all the humans in the Matrix were assimilated by Smith. By the time of the final showdwon between him and Neo, Matrix-Earth was basically a planet of Smiths; he'd been replicating himself exponentially. This is a convenient way for the Wachowskis to avoid the ugly reality of having Zion's residents deal with a few hundred million unwilling "freed minds" and the never-before-used but very hungry mouths that come with them.