By the bracketologists...
http://www.bracketmatrix.com
http://www.bracketmatrix.com
I don't see both Oklahoma and Kansas getting 1 seeds. Its hard for 2 teams from the same conference to both get 1's since they both play in the same conference tournament.
Plus, history. Here are the 1 seeds and their conferences from the last 6 years. I'm too lazy to go further back, but there hasn't been two teams from the same conference get 1-seeds in at least 6 years. So its very rare.
2015's 1 seeds: Big Ten, ACC, SEC, Big East
2014's 1 seeds: ACC, Pac 12, SEC, MVC
2013's 1 seeds: ACC, Big Ten, Big 12, Gonzaga (?)
2012's 1 seeds: SEC, Big Ten, Big East, ACC
2011's 1 seeds: Big 12, Big East, Big Ten, ACC
2010's 1 seeds: SEC, Big East, Big 12, ACC