Norwegian is getting some heat at Cruise Critic's message board for changing its policy about kids under the age of two. They used to be free, and now they're considered to be kids, period, so they will pay (well, their parents will pay) the same price as if they were all grown up (three).
Time for a little perspective.
Norwegian is now doing what other cruise lines do, which is discounting fares for the third and fourth passengers in a stateroom. Disney is being held up as something of a model, because the discounts for kids under three years is larger than the other lines. However, Disney fares are higher so it's important to check the bottom line.
So let's do it.
Using February 2013 as the time and the Caribbean as the place, here's what a family of four with both kids under three would pay (including taxes) for an inside cabin, for a week:
Disney Fantasy $3,538.08
Royal Caribbean Allure of the Seas $3,347.56
Royal Caribbean Freedom of the Seas $2,546.92
Norwegian Pearl $2,293.64
Caribbean Princess $2,133.88
Carnival Freedom $2,158.96 (six days)
While Disney and Royal Caribbean show discounts for kids, the others in this straw poll just show discounts for the third and fourth "people" in the stateroom. Only Disney asks for ages before computing the fares.
Norwegian previously charged a small amount (presumably just taxes) for infants. Now, instead of being chastised for changing, maybe Norwegian should have been credited with offering such a good deal as long as it did.

Norwegian's Pride of America
7 nights
September 30, 2012
Honolulu (return): Kahului, Hilo, Kona, Nawiliwili
Inside: $1,099
Cost per day: $157
www.ncl.com