Book 5 spoilers
As to Tyrion, this'll be his season. He has more chapters in the second book than any other character (Ned had the most in book 1)
Finally, for those asking what is/isn't in the book: in the books, every chapter focuses on the experiences of a single character and their point of view (though it is told in third person). If the following characters are not in (or witnessing) a given scene, it is not in the book: Bran, Catelyn, Daenarys, Arya, Jon Snow, Tyrion, Sansa, Davos and Theon. Every single scene in A Clash of Kings (except the prologue, which focused on the old man who was poisoned in this last episode, and the only scene he wasn't with Davos was cut anyways) has one of those characters in it.