The talk of a brokered convention is just that.....talk. Fl votes Tuesday and then comes Super Tuesday. Guiliani, McCain, or Romney will take a commanding lead on Super Tuesday. The states with a March primary (IIRC includes Ohio, Texas, & some others) will likely decide the contest.
And if this goes all the way to the convention it is hard to see the delegates turning to Fred. After all, Fred proved he can't win votes in the primary. Gingrich and Jack Kemp are two names that come to mind if a brokered convention turned to someone other than contest winners.
OTOH it is hard to see this happening. I think the primary contests will settle the matter. Huckster may trade his delegates to the leader, if the are needed to put him over the top, for the VP spot. Or Guiliani, if he does poorly, may trade his delegates for some cabinet post or other.
I would not hold out much hope for A) abrokered convention, or B) Fred getting the nomination in a brokered convention.