All those who are on the Android 1.6 platform need not worry anymore regarding the fate of Google Maps Navigation on their devices. The considerate folks over at Google have released the Google Maps Navigation App for devices running Android 1.6 (Donut) and higher, like the T-Mobile myTouch 3G and the G1.
The GPS app for Android 1.6 also supports the new Layers feature, which lets you overlay geographical information on the map. However features like the " ability to use the "navigate to" voice command is unfortunately missing in the 1.6 version.
You can download Google Maps Navigation for Android 1.6 from the Android market.