The prospect of Giambi spending most of his time at first base may make Yankees' fans cringe, but if I'm Joe Girardi, I have to try it before going with Ensberg, Duncan, or Betemit. Sure, there are some out there who will argue that Giambi's inevitable errors may shake the snowflake-like confidence of petrified youngsters Joba, Ian, and Phil, but I'm guessing the utter lack of offense from a power position may shake them more.
And yes, I realize that this article is heavy on the "best shape of my life" stuff, but that may be trumped by the fact that, for all practical purposes, Giambi is in a contract year. He's motivated to play some first base to maximize the potential offers next year, so I am inclined to believe him when he talks about his workouts and commitment.
Worst case: he is an utter failure at first and he goes back to being a full time DH. Best case: did I mention the lack of Duncan/Ensberg/Betemit at-bats?