First Read makes a good point here:
At a fundraiser in New Mexico last night, McCain cracked this joke at Romney’s expense: “I’m appreciative every time I see Mitt on television on my behalf. He does a better job for me than he did for himself as a matter of fact.” Bada bing. If McCain can start joking about someone, you know they’ve made it into his mental inner circle. Romney may very well be higher on the short list than anyone realizes. The biggest roadblock for many in picturing a McCain-Romney ticket is McCain getting over his personal reservations about him. But joking about him is a start.