If Giuliani wins the GOP Primaries, I am voting Constitution Party in the General. Period.
I may or may not decide the same for McCain or Romney, but with Giuliani I've already made my determination.
(Unless they run a joint ticket with the Constitution Party, I do not expect my oft-favored Libertarians to run a pro-life candidate in 2008)
I hear a lot of talk among Libertarian (with the capital L) leaders about supporting Paul. I think a lot of political support will come from the LP regardless of whether he gets their formal nomination.