No brokered convention.
It won’t happen, and if it did, it would result in a McCain-Huckabee ticket, guaranteed.
See, it’s already a two man race, and so for this to happen it would mean both Romney and McCain would need to be below 1,191 delegates, with Huckabee holding the remainder. After first ballots, Huckabee would deliver his delegates to McCain, putting him over the top, in exchange for the VP spot.
Wishing for a brokered convention in hopes of any other outcome would be like hoping the Super Bowl ends in a tie and the Miami Dolphins are declared the champions.
I'm not sure it works that way. I thought someone here indicated that after the first or second ballot the delegates would no longer be tied to a candidate and could vote for whoever they wished. Not sure, perhaps someone can clarify what the rules are.