You can download your local area and the area of your destination while you're still at home and on WiFi, which means you can avoid hefty data or roaming charges while still getting to where you need to go. In other words, you no longer need to be constantly connected to the internet to get around. As far as I am aware, this only works for offline viewing of maps rather than offline navigation.
The feature, which is hidden within the Labs menu of the Maps application, can be found by pressing the capacitive menu button when you're in the app then tapping More > Labs > Download map area.
To download a 10-mile radius square from any location on Google Maps, just hold down on any point on the map, click on the pop-up and select "Download map area." If you're selecting the radius from a previously starred location, just open the Places page and selecting "Download map area" from the "More" menu, which can be easily opened by pressing your Streak's menu button.