The curtain is about to be lifted on Google’s mobile progeny, but it looks like online retailer Amazon has spilled at least some of the beans on the device.

The web store said Tuesday that the T-Mobile G1 will come preloaded with Amazon MP3, allowing users to search, download, buy and play music from a catalogue of over 6 million DRM-free tracks.

Downloading music from Amazon MP3 on Android requires a wifi connection but searching, browsing, listening to samples and buying MP3s can be done over cellular. Tracks can be managed by any music library software and transferred between and played on different devices.

Of the device itself, Amazon said the G1, “combines full touch-screen functionality and a QWERTY keyboard with a mobile web experience that includes the popular Google services that millions have enjoyed on the desktop, including Google Maps with StreetView, Gmail, YouTube and others. With a fun and intuitive user interface and one-touch access to Google Search, the T-Mobile G1 is also the first phone to provide access to Android Market, where customers can find and download unique applications to expand and personalize their phone to fit their lifestyle.”