Depends on who that someone else was. I can't think of anyone who might have energized the base more, but someone like a Cantor might have energized the base as well and attracted voters from other demographics.
While I think Sarah will make a fine president one day, many people do not (2/3 find her unqualified). That is data we need to deal with no matter how much we like her. And, I really like her, and hope that she will become the first woman president one day down the road. She's got plenty of time.
However, we would be naive and setting ourselves up for failure if we think she will be elected president without serving as someone's VP first (sure, we'd vote for her -- well, maybe not you -- but the dems and indies won't).
The McCain staffers' handled her rollout incompetently and the MSM tarnished her reputation mercilessly. She will need to rehabilitate herself -- and she can.
If she really wants to be president one day, her best bet is to serve admirably as someone's VP. With McCain possibly serving only one term, this would have been the perfect opportunity for her to use her VP term to win the presidency in 2012. But it wasn't meant to be.... this time. She will be back.