As this race continues, I think that it will be Romney who will look and sound more Presidential to prospective voters, while McCain will fade. I would expect Mitt to continue with strength.
As a caveat, however, I don’t know quite what to make of these ever-changing poll numbers.
Romney reminds me of a GOP John Kerry.
Running on a TV persona of statesmanlike "gravitas" rather than true substance.
(Though Kerry's was shattered when they caught him in that bunny suit.)