Apparently the Tmobile G1 Android update I got earlier (http://www.chilledoutbeardedman.com/2009/06/01/g1-firmware-upgrade-to-slick/) is the infamous long awaited Cupcake update.
Some more feature updates that I’ve noticed on my G1 phone:
The camera can now shoot video.
The browser zooming has a button to return to the standard zoom.
The browser zoom box magnifier is better.
An onscreen keyboard with autocomplete that you load by tapping on a text field.
The camera loads up a little faster than before and has two onscreen buttons. In the top left corner is a small thumbnail of the last photo or video you shot. And in the top right corner is a button that you can use for taking photos.
Still missing zoom on the camera (though technically you don’t need it cause you can crop it later and its a high enough quality photo that cropping is feasible).
If you don’t have the updates, yet, those are some of the things you can look forward to getting in the near future.
As far as when your phone will be updated with G1 Cupcake update… I received the phone the day it came out and I received this update at about 8am PST. Two of my friends who have the G1 have not yet received the update. The first friend got the Tmobile G1 in mid-November 2008 and the second purchased it in Febraury 2009.
After I wrote all of that I discovered a full list of the new Android features here:
http://developer.android.com/sdk/android-1.5-highlights.html