On the referendum, my view is that whether or not the referendum goes ahead, the south will declare independence. That's an interesting question for you, given your history in Canada.
The question of Abyei will really depend on how they share the oil and the status of the Misseriya. If the Misseriya are allowed to vote and the oil can be shared, they can work it out. If they can't, you're looking at another kind of Kashmir situation on a smaller scale, because the population is small. You're talking about a population of about 35,000 people, not three million, but it would still be significant.