Baseball America has a nice chart up showing just what a dramatic turnaround the Astros' farm system undertook this season.
In short, among teams based in the United States, the PreStros were a cumulative 70 games over .500, 13 better than the 2nd-place Rockies. This is nuts, because in 2011, the Astros were a cumulative 138 games under .500 - a turnaround of 208 games.
Future divisional opponents finished 2012 as such:
Mariners: +43 (4th)
Rangers: +24 (9th)
Athletics: -5 (21st)
Angels: -71 (30th)