I was lured in by a "must see keynote" headline on a blog I followed, and ultimately ended up watching and thoroughly enjoying this fantastic keynote, presented by Jeff Greason at the ISDC 2011 Conference just recently:

Mark's comments:
I have to say, that while he is clearly pushing off-world colonisation, I really enjoyed his analysis of NASA's current strategy and his recommendations.

I personally feel that it is flawed to have any one nation pursue a colonisation strategy, and that somehow we need to change the conversation so that it becomes a 'planetary goal'. Having that built into each space-faring nation's strategic goals would make sense, and it would be far more viable, productive, and cost-effective than any one country trying to go it alone, for glory or national supremacy. It is very unlikely that a trade-route to an off-world destination will be cost-effective for a single country (although some asteroids do hold the potential to change this), but providing a "backup for humanity" in a second habitat does make sense.