I was just looking at my home city, Stoke-on-Trent, UK (population: 249,000) on Bing Maps; I had an idea for how to make the maps more user-friendly.
The name of the much smaller neighbouring town, Newcastle-under-Lyme(population: 124,000), is displayed in much larger font at all zoom levels, and is shown at some zoom levels where Stoke-on-Trent does not appear at all.
A city with the same population size as Stoke-on-Trent is Wolverhampton (249,000), which is in a bigger still font - as is nearby Stafford (population 131,000).
Stoke-on-Trent is the 16th most populous English city (http://en.wikipedia.org/wiki/List_of_cities_in_the_United_Kingdom) - I'd expect more people to be trying to locate it on a map than Newcastle-u-Lyme or Stafford. Therefore, making the "Stoke-on-Trent" font size the same as that of Wolverhampton would be a useful change.
I'd be interested to hear whether you agree.