It's easy to predict who's going to be cast as Danny! It's Derek. He's even better looking than Travolta and I think they would have passed up on Travolta if Derek was there. Derek looks much more the part and is better looking than all the rest of the guys.
As far as the girls are concerned, I can't yet tell. I thought they focused an awful lot on that one girl who didn't want to work tables back home if she didn't get the part. I was surpised they let her go. She had the best look for the part but she came across as so desperate and needy.
I thought it was interesting how last week a boyfriend/girlfriend pair broke up when he got accepted and she didn't. She was far more talented and attractive than him and should have been accepted. But I think the competition among woman is stronger because more women go into acting than men. Consequently, the judges had to scramble to take whatever males they could get that had any semblance to the role.
I think the producers did a good job to make the show interesting with the back stories, although there really doesn't seem to be much going on behind the scenes.