I think the Cards will win in 7. The reason is pitching, surprising enough.
The Cards have the best pitcher by far in Carpenter, and right now he will go against Trachsel twice. If it goes 7, and you have that match up it is the Cards all the way.
Game 1 is Glavine vs Weaver. While the season stats easily favor NY, I think it is much closer than people think. in his last 12 starts Weaver is 5-2, with a 3.88 ERA, and 1.32 WHIP. His performance the last 10 games is compareable to Glavine for the entire season. Weaver will go twice (unless there is a sweep), and he has to win once. I hink he can do that.
Game 2 is Maine vs Suppan. Maine is the best Mets pitcher, not Glavine, but Suppan is still a decent pitcher. I think he can beat Maine once, but even if he doesn't, if they get 2 wins from Carpenter and one from Weaver, that leaves the Marquis vs Oliver Perez game. Now Perez has shown that he can absolutely dominate, but he is either really good or really really really bad. He hasn't made major improvements since he came over to the Mets, just marginal improvement. I think the Cards should be favored in that game.
Basically the Mets must get 2 wins from Maine, and 2 wins from Glavine, because Trachsel isn't going to beat Carpenter, and they can't let the series hang on Oliver Perez having a decent start.