The biggest change is the addition of Transit Navigation, which is really nice for somebody that gets around using buses.
I've found myself lost in downtown Boston on a few occasions during the past few weeks, and thankfully my EVO will now be able to follow me (using GPS) to get me off at the right stop (and tell me the price of the trip).
The only downside to using GPS is that the navigation will "work best" above ground. This is a bummer for when you're on the subway, but at least Google Maps will get you on the subway at the right time and tell you the name of your last stop.
Another nice addition in this update is the ability to download map data locally to your phone. This is great if you are traveling or just hate load times. You will be able to download a 10-mile radius from any point, but you must go through a few steps to enable the feature.
First, hit the menu button while in the Maps app. Then, tap More and go to Labs. Once in the Labs section, simply tap on "Download map area." Then, choose/search an address (or simply press your finger down long enough) to find the middle of your downloaded data. Once at your location, you will notice a new "Download map area" option at the button of the page. After selecting you will have to wait several minutes for the download to complete.
Voila! Now I will never be lost in Boston again – even if cell towers go down. As you can see, the downloaded map data will help you when service is unavailable – even down to that nifty 3D building view.
Thanks for the new features, Google!