This is how it would go down.
Tell Icahn we talk after he has a new board. When all Icahn's cronies are on the board, pull back and say no deal. Watch as Yahoo stock plummets because the board has no clue how to actually run the business. Make offer of $10 per share and chuckle inside as Icahn losses a fortune for butting into other people's affairs.

All very predictable, Microsoft moves another competitor to the ex-competitor graveyard, and big stinking rich 'investor' makes a load of money on the back of hardworking people.
Excuse me while I try to suppress an involuntary gagging reflex...