Assuming your wife is educated, you come out ahead with her working. We pay $200/wk for two infants. My wife brings in $642/wk. We would be giving up that remaining $442 if she stayed home.
My wife is educated, so yeah she brings home a fair amt. However, you have to take into account geography. 200/wk for two infants would never happen at any reputable place where we live. Most folks we know are paying about 800/mo for the first child, with a discount for the 2nd. still going to be closer to 1200/mo.
We don't have kids yet, but it's her decision with what she wants to do about working. I'd prefer if she stayed home b/c that's how I grew up, but it's her call. I can totally understand the point many make - working and having kids can be a lot of stress, especially on women. I'm all for equality and whatever, but I haven't talked to one mother yet who's said it was easy to put her kids in daycare. It just introduced another level of stress.