If I had to take guess for Columbia, I would say either internal hire or Kevin Jermyn from Duke. The reason I say Kevin Jermyn is because he has experience recruiting in a strong academic environment. He consistently got great recruits (although he didnt do much with them). However, I think if this was the case, the announcement would have come out at the same time as his resignation. Thats why I am leaning towards internal hire, maybe Liam BP.