The brand was languishing. The public dismissed it as outdated, uninspired, and a little stale. So in a bold move, a new public face was anointed — young, appealing, and energetic. It’s a script we’ve heard before, whether it’s yesterday’s much-lauded announcement that Google executive Marissa Mayer will become Yahoo’s new CEO or John McCain’s ultimately disastrous choice to pick Sarah Palin as his vice-presidential running mate.