Post from: Google And Blog
Android Cupcake is Now in a Donut

Android 1.5 CupCake release has now been fully merged into Donut which in turn is merged into the Master Android release, so now its just a matter of the final preparations to release it to the current G1 phones.
After adding the CupCake statue next to the Mike Droid robot last week, the question is will it be joined by a Donut one in the near future.
Donut is a new release branch after CupCake which as of now is completely identical to the current CupCake code.
Google Android engineer JBQ affirms that the master release will be going forward the most active and bleeding edge Android codebase after Donut is completed.
I think CupCake will finally be released to the masses by the end of this week as HTC has today released it for the Android Developer 1 phones - ADP1 - with these upgrade instructions.
Now its a matter of getting the instructions finalized and simplified for the OTA update from T-Mobile for the G1 Dream phones.
This is made easier to get by the previous update as you can now simply check by going to SETTINGS > ABOUT PHONE > SYSTEM UPDATES

