Bear with me today...

Humble Elias has a lot of ground to cover:

Firstly John McCain is inviting over prospective Vice Presidential Candidates for some simple down home countrified eatin'.
The three men cited in the above link all have their quirks and deficiencies.
Florida Governor Charles Christ represents important electoral real estate to the GOP, but he has been dogged for years by rumors that allege he is gay.
I just don't see the GOP taking the chance...Romney's old supporter Jeb Bush might be a better bet if the name alone wasn't a synonym for a certain greedy ruthless ineptitude.
Louisiana Governor Bobby Jindal is a fresh face with no enemies and some reformer props...but the GOP has Louisiana in it's back pocket and McCain need someone to fetch the slumbering GOP conservative base. Jindal was only elected in'06 he may also be a tad too fresh to the Powers that Be.
And then there is Willard Mitt Romney, duly puffed up by the Boston Globe by this howler:
Romney would bring management experience to a McCain presidency. Whereas McCain's specialty is foreign policy, Romney has domestic policy expertise

Mitt Romney wouldn't know domestic policy expertise if it blew up in his face! He did nothing for four years as Governor of Massachusetts except go strolling before the TV cameras during snow storm, sign a health care bill that was written by others and ineffectually attempted to veto various items personally offensive to him.
The man is no John Kenneth Galbraith, he is hardly on a par with Arthur Laffer!
A political dilettante is what Romney is, pure and simple...craven and more nakedly opportunistic than most. He can't deliver Massachusetts and if the GOP can't fetch Utah then the depths of the Earth have opened up and poured forth the righteousness of the Lord.
Oh and one other thing, Mitt Romney chickened out of the Viet Nam war by the usual bureaucratic mumbo jumbo common to boys of his class and station. While McCain rotted in a Hanoi prison, Mitt was doing Mormon missionary work in Paris France.
Given all that, I wouldn't put it past Romney to be conjuring with another run for the US Senate here in Massachusetts...all his wingnuttery forgotten by him and Scot LeHigh at the very least.

Oh and there are also rumors that Joe Lieberman wants it as well, however last time I checked Joe was pro-choice and I firmly believe someone so disposed cannot be nominated for national office by the GOP. But then he could change his mind, but the season is late so he'd have to be extra special craven about it.