Being a Detroit Tigers fan I've seen how your home field can be a detriment to some of your big bats. That's whta happened when Comerica Park first opened. Eventually they shortened the fences, but it's still regarded as a pitcher's park. Minnesota Twins first baseman Justin Morneau isn't taking a liking to Target Field.
“Right-center to left-center is ridiculous,” Morneau said in an e-mail to the Minneapolis Star Tribune. “(It’s) almost impossible for a right-handed hitter to (homer to the) opposite field and very difficult for lefties. It affects the hitters a lot, and you start to develop bad habits as a hitter when you feel like you can only pull the ball to hit it over the fence. You take those habits on the road.”
Be careful what you wish for. If you move the fences in, it could give visiting teams the same advantage that your looking for.
There are discussions about moving the fences in, but it's not imminent.