I voted for extinction as the most likely but personally I'd like to see all of the above without the extinction.

Next logical evolutionary step for humans is to take the approach the finches took to the Galapagos islands but on a galactic scale and fill all the niches we can find. In a similar manner to mankind in Stephen Baxters Xeelee series of books, with mankind living from the surface of the stars, to the deepest oceans, to the empty void of space and even in alternate/parallel levels of reality where the fundamental building blocks of physics themselves are different. In fact a lot Baxters novels concern the survability of humanity into 'deep time' and the steps we need to start taking now.

Chances are very good however that we'll end up wiped out before too long, by are own hands or not. Btw good poll question ^__^