Have you even played around with Mcedit a lot? I'm sorry, I'm obviously not being clear here. I'm looking to generate a new world 500 blocks by 500 blocks (or more). As far as I know (and I could be wrong, if I am please correct me) McEdit doesn't have the ability to randomly generate a new chunk.
Does anyone know of a program which has the same land generating capability of Minecraft, which will save me the trouble of walking around the map until I have sufficient land generated?