This kind of suprises me considering how frequently Bo redshirts freshman. If they were already ineligible, no one would redshirt their freshman year. That means we'd have a ton of guys playing 3 years instead of 4...because those that get time as redshirt freshman (martinez) would end up playing as sophomores and never use the redshirt. We might have 3 more years of Martinez as is currently. Had he been ineligible as a freshman, he would have been playing as a sophomore last year and we'd only have 2 left. It would reduce the number or redshirt players considerably and help w/ the scholarship numbers that's for sure.
You also might see more kids graduating...instead of playing 3 years and heading to the NFL. To get 3 years in, you'd have to be playing as a senior which means you're more likely to have that degree. Some would leave after 2, but most need those 3 years to have enough NFL stock to leave. This would boost the average age of the starting squad some, and maybe the quality of football on the field. Especially on teams like Alabama/Florida/USC/Texas where they recruit a lot of top end talent...then see them leave after 3. Now all that tallent we are happy to see go, would be around for another year. Alabama w/ Ingram another year, or Oklahoma w/ Bradford another year. Not exactly teams we'd have enjoyed facing. Since Nebraska, historically, doesn't have a lot of players leave early anyway...we'd probably be at a disadvantage from this perspective.
On the other side of that, it might level the recruiting field some...as the "play right away" argument would be gone. Teams like Texas that historically play a bunch of freshman would be at a disadvantage early on.
It would certainly change a lot.