If he had won Florida, he might have managed to win a couple more states but McCain would still win. The only difference is McCain might pick Giuliani or Huckabee or someone from the other wings of the party as his running mate. For example, Elizabeth Dole or Condoleeza Rice.
If Giuliani won New Hampshire, he'd probably win Florida, Hawaii, Maine, Michigan, and maybe Nevada, cementing himself as the front runner. I think he'd win the nomination.
324: Senator Barack Obama/Senator Joseph Biden - 51.3%
214: Fmr. Mayor Rudy Giuliani/Senator Elizabeth Dole - 47.6%
Others - 1.1%
Keynote speakers/main surrogates would be Evan Bayh and Gavin Newsom, and Charlie Crist.