According to fresh data from Rasmussen Reports, Sarah Palin's selection is a mixed bag. Voters have a favorable impression of her by a 53/26 margin; however, by a 29/44 margin, they do not believe that she is ready to be President. Needless to say, the PR battle over the next couple of weeks will involve the McCain campaign playing up her biography, and the Obama campaign playing down her readiness.
At this stage, it is not clear how impactful her selection will be: 35 percent of voters say they're more likely to vote for McCain with Palin on the ticket, and 33 percent say they're less likely. Indeed, among voters already committed to one or the other candidate, her choice would seem to do little bit entrench partisan feelings: just 6 percent of McCain voters say they're less likely to vote for McCain with Palin on the ticket, while just 9 percent of Obama voters say they're more so. (To see how Joe Biden's numbers compared -- see here. As might be expected, Biden scored better on readiness and worse on personal favorables, with the other numbers being about the same).
What's interesting, however, is that while there is a gender gap in these numbers, it's not the one many observers were anticipating. Rather, along a variety of metrics, men like the Palin choice better than women:
http://www.fivethirtyeight.com/2008/08/women-more-skeptical-of-palin-than-men.html