On further reflection, the Rice issue raises two problems...
1. Condi doesn't want the job..
2. Her abortion stance really makes her a non-starter anyway, especially since Mitt promised last year that his VP pick would be a conservative, pro-life pro-"traditional marriage" person. He can't afford to piss off the Tea Party, as we saw in the mid-term elections. The Tea Party will happily strike down the GOP ticket if he doesn't pander to them.
He may be able to convince Rice to run in some kind of patriotic call to service. But I think the damage it would do to his campaign would kill it off.
Rice is still tainted by Gulf War 2. Independent voters would be turned off by that. Conservative voters would be turned off by her abortion stance. Is she qualified to be "a heartbeat away from the Presidency", given the fact that she has never held elected office before? Expect left-leaning commentators to make hay with a line like "even less qualified than Sarah Palin".
I reckon he'll go for Rob Portman.