Here is my opinion...
Jimmy Clausen will be the starting QB. I don't think there is one aspect of his game that you can say is weak. If anything, it would be the experience factor. But being a year older than most kids in his class, means that he is about the same age as DD and ZF. Also, his EE status gives him the Spring to catch up a bit. One of the greatest praises about him is that he is maybe the most fundamentally sound QB to come out of HS in 10 years. That should mean he is ready to play, especially when none of the QB's currently at the position have any considerable playing time.
Another thing to note. One thing that separates him from just about any QB fresh out of HS and most on any CFB roster is where he hits his receivers. From every tape I have seen, including yesterdays full tape of practice, he hits the receivers perfectly in stride, where they don't have to adjust to the ball. I think his deep throw can use a little work, but his crossing patterns seem flawless. When comparing them to the other QB's. The other guys might complete the pass, but JC seems to complete the pass in the best position to get them to make a play.
The only question would be if he has the "leadership" factor, especially as a guy that just got here in January. I believe that he does. I believe he is vocal and will be a good leader for his team. He had to lead his HS team as a sophomore, and did so devestatingly, so I believe he can lead an older group as a younger guy.
DD will not start, I would love to see him in action because he is the most dynamic out of everybody. But the issue is that ND with CW at the helm is not a team like WVU or Navy. I know DD is a good passer. But it doesn't appear that his passing is on par with JC's, ZF's, and maybe not even ES's. He is a good decision maker and has all of the leadership qualities that you would want out of a QB. I just believe that he is in the wrong system to take full advantage of his talents. It's too bad, really.
I think the only way he would ened up starting is if he proves that he can pass as well or better than any of the other QB's. If that happens, CW can then use his normal offense, more or less. And take advantage of DD's legs by creating some opportunities for him to run a little bit more. But he will have to prove that he is the most proficient passer first. And I just don't see that being the case.
Zach Frazer will not start simply because of his leadership qualities. Now I am acknowledging here that this opinion is just that... an opinion. I have heard some rumblings from many people still attending ND that ZF doesn't seem to have a good attitude or be a natural leader. At least not when comparing him to DD or JC. Maybe it is just speculation though. He does have tremendous passing tools. Probably the best arm, easily the best build in regards to a pro-pocket passer. I just feel like he doesn't have that intangible, he doesn't have that confidence. It seems faked to me. And CW is obviously one that looks at the "it" factor a lot.
Evan Sharpley will not start because baseball will get in his way, and because Weis simply won't have a half baseball player and half starting QB for ND on his team. I feel like Jeff could have been better last year, and it seemed like it was because baseball was on his mind. Same with Zibby and boxing. And at QB of all positions, you can't be distracted.
Sharpley is a good passer, but he doesn't have the velocity of any of the other guys. His balls loop a lot. That may work consistently in practice. But when you compare where the ball hits the hands of receivers, JC is far ahead of him. Sharpley hits them in the middle of the body consistently. JC hits them in stride, where they have a chance to make a play.