I'm not predicting a pennant but I'd disagree that pitching is a major problem. Who, in the NL, has a stronger staff?
Arizona? Once you get past Johnson and Schilling, what do they have?
Atlanta? Now that Glavine and Millwood are gone and Smoltz is in the pen, they have to rely on Maddux, Ortiz and what's this? Mike Hampton?
Philadelphia? You might have something there but it's not exactly a stable rotation and they still have a shaky closer.
The Dodgers, Cardinals or Giants? Lots of question marks there.
Houston has two starters (Oswalt and Miller) who are among the top ten in the league and have Cy Young potential. The bullpen is anchored by Dotel and Wagner, among the best set-up and closers in the NL. After those four, they have a lot of question marks but then so does everyone else. And the rest of the league doesn't have a heart of the order like Bagwell, Berkman and Kent.
A lot will need to go right for the Astros to win it all but I wouldn't write them off so soon. Talentwise, they're at least on par with the rest of the league.