First off, that's a load of crap. Pitching alone does not win titles. Pitching AND hitting wins titles.
Second, I don't know where this attitude comes from that the Cubs are easy favorites. They added Maddux. The Astros added Pettitte AND Clemens. That's on top of Wade Miller and Roy Oswalt. On top of that, the Astros scored 75 more runs than the Cubs last season, and the Cubs really haven't done anything significant to their offense.
Third, I'll be shocked if that pitching staff lasts the season with Dusty Baker's reputation for overuse.
Fourth, the Yankees are not lightweights in the pitching department. Kevin Brown will reach 200 wins this season, as will Mike Mussina. Javier Vazquez is even better than those two. Jose Contreras is a competant #4, and you only need four starters for the postseason.