What is neo classical ballet?

Neoclassical ballet is a type of ballet formed by George Balanchine and is "American ballet" (like Vagonava is Russian Ballet).

This type of ballet makes everything bigger and grander so instead of small controlled jumps, for example, in Balachine/neoclassical ballet, there would be huge jumps. Another example is when you finish a pirouette in fourth position, some styles have you end in a small fourth, but in neoclassical ballet, you land in a wide fourth with arms lengthened and "reaching."

Source: http://en.wikipedia.org/wiki/Ballet (under neoclassical ballet)