Google G1 is not old yet, ZFr3eak and yohshua from XDA-Developers have managed to port Android 3.0 (Honeycomb) to the T-Mobile G1 and HTC Magic. They have not release any alpha stage yet but they were able to show a video showing their G1 and Magic running Honeycomb.
Honeycomb is a version of Android for tablets. Honeycomb of the G1 is still missing SMS, 3G, WiFi, and Bluetooth support, but the development team has managed to enable the Honeycomb keyboard, Data / apps, multi-touch, LED, and keyboard lights.
T-Mobile G1 Honeycomb ProjectHTC Magic Honeycomb Project