I think that too many delegates are Cruz loyalists for Kasich to win. Cruz has been playing the delegate game with uncanny skill. The rules won't change without the support of the rules committee, which is going to be populated with a lot of Cruz and Drumpf loyalists. They'll have no reason to change the rules, which means that (provided Cruz can get a delegate majority in one more state, I think he's only at 7) those two will be the only ones eligible for a vote.
But I do agree that Kasich would be the smartest move for the GOP if they could pick him. Sure, they'd piss off a huge section of the party, since 80% of people didn't vote for him. But the question is really "would the base fall in line for another Romney in order to stop another Obama (or worse)?" I think the answer is yes.
Anyway, I'm still predicting Drumpf wins it, and I think he'll win it with a pledged delegate majority.