There is virtually no contempt between north and south koreans (the common people, anyways). I've been to Korea, and most people (north AND south) desperately want reunification, and are deeply effected by the status of a divided Korea and a divided national identity -- even though its been so long.
Amid all this speculation, we should remember that China has a treaty with NK to help defend it should it ever come under attack. If USA decides to move carriers in and bomb them, they will have awakened the sleeping dragon. (Dejavu - anyone remember how the 1st Korean war ended?)
Unless, of course, China decides to ignore the mutual defense treaty. I'm not sure how that would look to its other allies though.