Thoughts on Sarah Palin. She's clearly the long-shot choice, and McCain's choosing her likely means he has internal polling data that suggests without significantly mixing up the race, he's going to lose. Second, the attacks on her family are reprehensible and Obama is correct to declare her family off-limits. However, positions regarding the issues surrounding teen pregnancy, abortion, raising children with disabilities, and the like are quite important, and should be discussed.
Finally, Nate at 538 makes some interesting points about the amount of experience you need from a
VP nominee compared to the Presidential nominee. He argues that the VP nominee needs to be more experienced than his or her running mate, as he or she will necessarily be taking office at a time of national crisis. The presidential nominee has two months to prepare for the position, select a cabinet, etc. A VP taking over for a deceased or no-longer-competent president is being thrown into the deep end of the pool.
Edit: My quite intelligent commenters have made the point that of the potential ways a VP could be promoted, only in the most far-fetched and unlikely scenarios would Palin be really hurt by her inexperience. In most cases, she'd probably be able to let the machinery of government handle the situation until she got on her feet. Score one for my readers. :)
Edit2: Upon further reflection, I think that a VP pick really says more about the candidate doing the picking than anything else. People don't pick candidates based on the VP, but as one of the key decisions of the campaign, it does say something about the candidate and the sort of administration that they would run.