We'd all be spread out across the solar system, tending our terraforming machines and growing weird crops in the sands of Mars.
Of course, we might just be polluting every planet we touch and bringing our stupid dreams of conquering the genome to a bunch of poor nonhuman creatures with no defenses. But I still miss that future of outer-space colonies. I can't help but think it would be better than the future we've got. *
Annalee Newitz is a surly media nerd whose Martian colony has a better space elevator than yours.