The Astros are rebuilding and have been very aggressive in their pursuit of prospects and getting rid of veterans. Players like Lance Berkman, Roy Oswalt, Hunter Pence and Michael Bourn have all been moved over the past two seasons in hopes of rebuilding a depleted farm system.
While all early indications are they have done a good job in stocking up, I don't think the Astros are done yet. They still have a number of veterans who probably won't be on the 2012 Opening Day roster. I have come up with four players who I don't expect to be back next season.