Iowa loses some computer love to Florida and now sits with the second best 1/0 average. That hurts their chances of jumping Texas if it came down to picking between several undefreateds.
Vegas has opened most of this week's lines as well. Through Penn State's loss to Iowa, Ohio State falling to USC and their inexcusable stumble against Purdue, the related lines seemed to suggest the two teams are nothing but equal.
For example: Penn State was a 3-point favorite in the preseason "Games of the Year" odds; both were 17-point home favorites against Minnesota; there was a 6.5 point difference between the lines against Illinois, however adjusted for home field (three point swing either direction from "neutral"), and it's within half a point.
It looks tonight to be settling right around Penn State -3.5, or put another way, with Penn State maybe a half point better but holding home field advantage.