I was most interested in the public transit schedule support since I find myself visiting the Sound Transit page if I need to jump on a different train due to a change in my schedule and that happens about once a week. Unfortunately, my Sounder train schedules are not yet in Google Maps. However, there are a ton of bus and even Washington State ferry schedules in there so it is still a very helpful layer to enable. The ability to view when the next bus or ferry will be available is extremely helpful and much better than just having a list of departure times. I wonder if the times change dynamically as real-time data is sent from buses, trains, and ferries?
Google Maps on the Android platform is one reason I am a fan of these devices with the superb Gmail support being another key factor.