Update: The feature was added in the October 2014 release, a few weeks after writing this note. See the short tutorial here.
One of the features in the soon incoming release of Premiere Pro is the ability to change clip names and labels project-wide. It’s a feature request coming mostly from the former FCP users, who were used to inflicting changes that propagate throughout the bins and timelines. It’s nice and I can see uses for it, but it also sets a very interesting precedent, which I believe should be exploited to push for another, much more useful feature – primacy of project metadata over file metadata. see more
