Google Maps added a lot of features in the past three years since it was launched without major interface changes. The application started to look cluttered with too many links, buttons and options, so a redesign was more than necessary.
Today Google Maps got a small facelift (compare to some screenshots from 2007) and I'm sure we'll see more changes in the next months. The search box is powerful enough to handle all kinds of queries, so it's not necessary to choose between finding locations and searching for local businesses. The option to get directions is still available and now supports address autocomplete based on your saved locations.
Google Maps homepage replaced the examples of searches with popular custom maps, showing that the application reached a new stage of development.
Update:Evan Parker from Google says it's only an experiment. "We're running the new UI as an experiment, so only a small percentage of users see it. If people like it better than the old UI then we'll launch it to all users after cleaning up the bugs and incorporating any changes based on feedback from the experiment."