I am pretty certain Luffy is going to do exactly what he said and 'tame' the Kraken. He DID, after all, tame those other animals on the island during his 2 years of training. And he is probably going to use King's Disposition to do it.

It would be interesting for the strawhats to have a pet Kraken. Maybe they can use it in the future to fight Sanjuan Wolf of the Blackbeard pirates.