She tells ET it would be a last resort, and even though she's said similar things before, watch the video -- particularly on the bolded text -- and it sounds like she's having, at least here in October 2010, some reservations.
"It's going to entail a discussion with my family [and] a real close look at the lay of the land, and to consider whether there are those with that common sense, conservative, pro-Constitution passion, whether there are already candidates out there who can do the job, and I'll get to be their biggest supporter and biggest help-mate, if they will have me.
Or whether there's nobody willing to do it, to make the tough choices and not care what the critics are going to say about you, just going forward according to what I believe the priorities should be."
If there's nobody else to do it, then of course I would believe that we should do this."
UPDATE: I took down the vid, b/c it kept automatically loading, but you can check it out here.
[Hat tip: NewsOk and Buzz Tracker]