Going from sputnik in 1957 to the moon landing in 1969, I can see how someone in the 70s might think we'd have space colonies by 2012. Then again, a lot of people thought we'd have blown ourselves up by now.

Of those two visions, we've come much closer to blowing ourselves up then we ever have to space colonies. I'm ok with the lack of progress on the space colonization frontier--I just wish there was more progress on the "how to not blow ourselves up" problem.