Jeff Creps posted his predictions today, with some reasoning, and the Astros were picked to finish dead last:
Since losing to the White Sox in the 2005 World Series, it has been a downward spiral for the once proud franchise. They inexplicably gave GM Ed Wade a two-year extension and continue to have one of the worst farm systems in baseball. With most of their star players in the twilight of their career, expect a complete rebuild of the organization sooner rather than later.