Yep, 4 cups is what I heard this very evening when I went to my first birthing class. But she didn't say whether that was coffe, or soda, or a combination. Since a can (8 oz) of soda has roughly 35-45mg of caffeine, and a cup (roughly 6oz) has about 110mg - well, you can see the difference.
Me I've stayed away from caffeine for the first 6 months. I've only just introduced caffeine back into my diet. But it's out of necessity. Can't find non-caffienated drinks in take-out joints, and I can no longer have the juice or sugared sodas (I'm gestational diebetic). But I'm told it's okay. Moderation is the key to everything! Remember, a Big Gulp of diet coke has the same, if not more, caffiene as a small cup of coffee!
So many no-no's when we get pregnant.