More like Sudan should have never been one huge country to begin with. The two Sudans were just incompatible culturally, ethnically, economically, etc. Add in the neglect that both the British, Egyptians, and North Sudanese gave to the southern region, and typical barbarian behavior in many parts of Africa (especially the Sudan), and you just can't be surprised that such a thing occurred. And it isn't scary that South Sudan wanted to get away from all that. Sudan should continue to be broken up.
As a matter in fact most African countries should be broken up into smaller countries and away from European drawn borders. It would create more peace and stability in the region.