It seems like a two-way race between Casey and Hung right now. I don't think the other two have a chance, unless something weird happens. Of course they judges have said they judge each contest independently, so anything can happen.
As this season wraps up, though, I think it is a weaker overall quality from Season 2, which I think was the strongest, in terms of talented Chefs of the three seasons.
By the way, people wondering about Casey under that coat, there was a Q&A show with people from all 3 seasons, and the judges and Q&A and they had one bikini shot of Casey laying out.