This makes me feel like your 88-year-old grandpappy, but MLB 10 will have the old Polo Grounds. Back in the day, its centerfield ad read "Always Buy Chesterfield," a cigarette. Guess SCEA didn't want a T rating for tobacco reference.
As we mentioned earlier, the Polo Grounds will be available as preorder DLC for MLB 10 The Show, but Sony clarified a few more details about the venues. They will be included on the disc and they can be unlocked for free, but you have to earn every trophy in the game. Platinum status on The Show takes a lot of doing, so Sony's definitely incentivizing the preorder for nostalgia buffs.