As someone who ran as a Romney delegate, I see Mitt as the best choice for VP (no bias here).
He seems to be the best choice of the choices presently under consideration, esp. if your number one consideration is the economy. There might be other "out of the box" choices, or perhaps some great unknown out there, but that seems a little risky to me at this point.
Let's face it, Romney has a lot of what McCain lacks: money, the ability to make money, friends with money, charisma, youth, mainstream conservative support, the ability to motivate people, gubernatorial experience, a strong economics background, and of course, great political hair!
He's already been vetted, never even a hint of scandal, a great family life, etc. Sure, Romney's good on most of the cultural stuff, too, but as was pointed out a lot in the campaign, he was something of a late arrival to that. Whatever appeal he has on a cultural level, I think his economics background will outshine that for most people. He's fairly conservative, but not as conservative as some conservatives would prefer.
As far as I can tell, Romney's only real drawback is that he's a Mormon. That is only a drawback among a segment of the evangelical Christian community who are afraid that this is part of their plan to take over America. I'm certainly not a Mormon, but I don't fear them. I'll go by the Constitution's prohibition of a religious test to hold public office anyday, as long as someone handles himself in office well. I don't think those who would hold Romney's Mormonism against him would be likely vote for McCain, regardless of who McCain chose for VP.
Even though they may be a bit of a political odd couple, there's plenty of precedent for that (i.e. Kennedy-Johnson, Reagan-Bush). The important part is that you bring the party together and have a coherent conservative message. Regardless of whether he's chosen for VP, Romney is definitely a top contender for 2012.
PS I think the GOP has finally found some footing with the energy independence idea (i.e. drill now, drill everywhere, more nuke plants, etc.), because it puts the Democrats on the defensive. It's a good example of turning a pretty bad economic lemon into political lemonade.
