I updated my T-Mobile G1 to the Haykuro 5.0G build a few days ago and I am loving it; it is more responsive and stable, it has much better battery life, more features, and –did I forget to mention- A2DP!
Google seems to be unhappy that the build ported from the UK was being used on the T-Moble G1 and disabled downloading from the App Store for this firmware version; That wasn’t very nice! At the same time, they announced the SDK for Android 1.5- i.e. what I am already running with the ported build!
Haykuro released a 5.0.1G-r2 version today that addresses the App Store issue- along with another version that allows Apps to be run from the SD (just remember to partition your SD card with a ext2 partition).
Google- please don’t pull a Sony on us by trying to keep ahead of the hacks!
Update on update: Hykuro 5.0.1 appears to have the Latitude version of Google Maps for the G1.