The first two starters that the Phillies will face in the series both have had success against the Phillies during their career. Tim Lincecum (2-1, 3.17, 7 GS) and Jonathan Sanchez (3-1, 2.86, 9 G) have both pitched well in their outings against the Phillies.
Lincecum will battle Roy Halladay in game one and conventional wisdom says that "The Freak" will have to help his team to a win in at least one of his two potential match-ups against Halladay. If Halladay gets wins in both of those outings, it's going to be extremely tough for the Giants to win the best-of-seven series.
Sanchez will be matched up against Roy Oswalt, who has done his best work of the season at Citizens Bank Park, where both of Sanchez and Oswalt's games would be taking place during the NLCS, giving Oswalt and the Phillies an advantage.
Where the Giants big three shows a chink in the armor is when the number three pitchers roll around. Matt Cain (0-3, 6.23, 5 GS) hasn't had anywhere near the success that Lincecum or Sanchez have against the Phillies and he'll be matched up against Cole Hamels, who has been second only to Roy Halladay in effectiveness both late in the season and in the NLDS sweep of the Cincinnati Reds.
For the Phillies, the key match-up will be when Oswalt faces Sanchez, since Oswalt has struggled slightly late in the season and was definitely a weak link in the Phillies series with Cincinnati. Both teams will likely feel the need to win game four when Joe Blanton matches up against Madison Bumgarner, the 21 year-old phenom who went 7-6, 3.00 in 18 starts for the Giants this season and was able to pitch well enough for the Giants to win the deciding game against Atlanta in their NLDS match-up.
Of course, playing in the post-season is very different from playing throughout the regular season. The Phillies have more battle tested post-season veterans than do the Giants and with two teams with excellent pitching going against each other, the series could actually come down to who can find more ways to score. That edge has to go to the Phillies, who have more team speed to go along with their power capabilities.
When all is considered, the series will likely be one to remember, but the Phillies simply have more weapons and can find more ways to win games than can the Giants. With that in mind, it's the Phillies in six.