It depends on how fast the media spins this.. if they convince the public that McCain has won then it's over whether it's technically correct or not.
The projections on CNN showing how Huckabee would have to finish with 50% of the vote in every primary (or higher) to get into a brokered convention assume Paul wouldn't finish well in any of the states (which... after VA, DC, etc.. is a realistic prediction) and McCain would come in second and pick up almost as many delegates. However - if Paul won TX (not likely at this point..) and Huckabee came in second then it would be a different game. Huckabee would begin picking up drastically more delegates than McCain. The Huckabee folks need to realize that they aren't going to a brokered convention unless Paul starts beating McCain. .. so a brokered convention isn't likely.