Yahoo will win, Icahn will lose
Once he puts his asset strippers in place, what then?
He can't break it up and sell the parts because they depend on each other for the traffic.
As a whole the only company with enough money to pay for it is Microsoft. If Yahoo board that grew the business can't extract a big enough fee, what makes him think he can with his subpar board in charge?
So what price does he think he'll get, $31 a share? 28? 24? 18?...5?
First lesson of selling, you never enter a negotiation fixed on one outcome. So you'd be stupid to put in a board focussed on a fixed outcome.