I spent a whole summer looking at that map of downtown London (I was living in the area) and feeling a vague sense of frustration in finding tube stops, restaurants, and local roads. But I could never have identified the specific aspects of the UI that rankled me. I'm glad there are people who can.

They're really making Google Maps smarter. Making the major thoroughfares stand out more is really clever and intuitive. Accounting for road width is also a huge improvement, especially for cities.

All in all, these changes make Google Maps work more like you'd expect it to. That might be why it doesn't seem that impressive on first glance.