As of early December, Google has added bold type to a selection of its place labels:

This treatment seems intended to bring greater attention to places receiving relatively high numbers of visitors, such as certain museums, big box stores, and grocery stores.

Alternatively, this new treatment might also be intended to enhance Google Maps’s overall readability. Other types of labels on Google Maps, such as country and city labels, are shown in different text sizes and weights…

…and this, in turn, adds hierarchy amongst the labels—which helps organize all of the info on the map and makes it easier to scan overall.

But up until now, place labels have largely been missing this same kind of hierarchy (i.e., they don’t differ by text size or weight—only by category color). Because of this, Google’s map often looks cluttered at zooms with lots of places—such as here in Manhattan:

So it seems as if this new treatment is also intended to enhance the map’s overall readability, by highlighting places of especially high interest: