Would be the best addition we could make if you ask me. Balances out the divisions and maintains everyone's major rival.
The question is - is Texas ready to kill all their rivalries (excluding Oklahoma and possibly one more) on a yearly basis? Academically and financially it makes a ton of sense.
Big Ten East: Indiana, Michigan, MSU, OSU, PSU, Purdue
Big Ten West: Illinois, Iowa, Minnesota, Northwestern, Texas*, Wisconsin