One place I think we have a leg up with Jacobs is the fact that wherever he goes he plans to enroll early. Thus, he's been preparing for Iowa since this summer, and he may not want to uproot the relationship with the staff and academic plans he's made up to this point for a school that, while they might be his homestate "dream" school, decided to slow play him to see if they could land somebody "better". Not to mention all the issues and speculation surrounding Urban Meyer at this point.
As for Bell, while I don't think it knocks Purdue out of the race, it's still a while before he's set to commit, and he can either go there and be a role-player in an, admittedly potent, passing attack, or come to Iowa and be THE guy early and often.
Overall, my gut feeling says Jacobs stays, but Bell goes PSU/OSU.