The benefit of FIP is that it takes into account how well a given pitcher pitches regardless of the defense behind him. The drawback, in my eyes, is that in only taking batted balls in the form of HR's into account, it doesn't tell the whole story.
The following formula takes into account all batted balls, and is, in my opinion, a much better metric.

[((FB-HR)*1.85121)+(LD*2.745645)+(GB*.56001)+(popups*.076)+(HR*6)+BB+HBP-K]/IP

Cards starters and ranks (I've only got guys w/>100 IP's - 142 guys):

Wainwright:  4.23 (49)

Wellemeyer: 4.41 (80)

Lohse:  4.51 (89)

Pineiro:  5.18 (129)

For whatever it's worth, the leaders are Joba (2.66), Lincecum (2.79), and Harden (2.81).

As always, any feedback (good or bad) is appreciated.