The Astros aren't exactly in an enviable position, with a farm system that's regularly ranked in the bottom-half of baseball, and a major-league lineup that's filled with AA refugees. As such, the team was having some trouble finding a GM to replace Ed Wade, with several prospects declining the opportunity.
The organization can take down the Craigslist ad, though. From Alyson Footer:
Astros confirming Jeff Luhnow hired as general manager of the Houston Astros. Formal announcement forthcoming.
Luhnow was the Cardinals VP of player procurement, and before that he was the VP of scouting and player development. The Houston Chronicle quoted a prepared statement from the Astros:
The Astros strive to develop one of the best systems in baseball and create a consistent winner at the Major League level. Jeff has the knowledge, skills and experience to lead the baseball operations efforts at all levels and help the Astros achieve this vision. Jeff has a demonstrated the ability to inspire and motivate staff in the front office and out in the field
If you want some insight as to what Luhnow's organizational philosophies might be, he gave an interview with Baseball Prospectus in 2008.