Buyers or sellers?
Neither, unless they fall out of the race, and probably not even then. General Manager Ed Wade says the Astros won't be buyers at the deadline.
Short-term need
The last few Astros teams have been perilously constructed--they pay four or five players obscene amounts of money, but then are thrifty with the back end of their roster, and they don't have much margin for error because they lack minor leaguers they can rely on. At any given time, the Astros usually have two or three players who are among the very best in the league at their positions, and two or three positions on the diamond where they don't field a starter who's even competent. It's a very strange balance.
This year the Astros have gotten very little from second baseman Kaz Matsui, though he's been modestly productive since returning in June from a hamstring injury, or from any their main bench players who aren't Jeff Keppinger. (Hey, Darin Erstad and Jason Michaels are terrible--who knew?) Otherwise, the Astros have been respectable, but it probably wouldn't be wise for them to continue to count on dubious veteran starters Russ Ortiz and Brian Moehler. Another starter, Mike Hampton, has decent numbers overall, but that's largely because of four excellent starts against the Pirates, against whom he's allowed three runs total in 27 innings; against teams with real offenses, he's been dreadful.
The question is whether the Astros acknowledge these weaknesses--they've exhibited an almost monastic level of patience with some of their most heinously unproductive hitters in the past, bringing back veterans like Erstad and Brad Ausmus year after year. Acquiring Keppinger earlier this season was the right idea, at least in terms of their immediate roster needs. But at the very least, the 'Stros could still stand to acquire one more hitter for their bench. With their limited trove of prospects and treasure, they may not have what it takes to acquire a good starting pitcher, if they even wanted to.
Long-term need
Sometimes one wonders if the Astros realize there is this thing called "the future" that will someday come and hurt them if they don't plan for it. Their farm system is a mess after years of negligence (see below), and they'll owe about $50 million to Carlos Lee, Lance Berkman and Roy Oswalt next year, as a number of their players, including Miguel Tejada, become free agents. Berkman and Oswalt are still very productive players and at least Lee can still hit, but that's a huge portion of their payroll going to three guys. The Astros are only three games back in a mediocre division right now, so they might well be justified in simply pushing all their chips in this trading deadline. The problem is that they don't have many chips to push; their 2009 payroll is already a bloated $103 million, and they don't have many prospects other teams would be interested in.
Big leaguers on the market?
There probably won't be any major leaguers on the market, unless things really go south, and probably not even then. "If the Astros shop anyone at the big league level it'll be Tejada, [LaTroy] Hawkins, or [Jose] Valverde, but... I can't see that happening between now and the deadline," writes Stephen Higdon, who blogs the Astros at Crawfish Boxes.
Minor league strength
Is it too mean to say "none"? The Astros' farm system has been embarrassing for years now. The 2008 draft brought a couple of genuinely good prospects in Jason Castro and Jordan Lyles, and top 2009 draft Jiovanni Mier is off to a good start to his pro career, but Houston has big problems at the higher levels of the minors. The closest thing they have to a near-ready player is pitcher Bud Norris, but even he is struggling with control problems at Class AAA Round Rock, despite a nice strikeout rate and ERA.
Take on short-term money to win?
"There's no way they take on any money to win," writes Higdon.
For more coverage of the Astros, check out Crawfish Boxes.