Well I just ordered my T-Mobile G1, I have been waiting for this phone for 2 years from when I first heard about it. I also wanted to share with everyone that you all can experiment with the G1 before you even get it. This is mainly for developers to test apps, but you can have fun testing the os, browser and some limited applications.
Howto: Install Google Android SDK in Ubuntu
sudo apt-get install sun-java6-bin
(If you are on a x86_64 system), you also must install ia32-libs:
sudo apt-get install ia32-libs
Now go to http://code.google.com/android/download_list.html
Download and right click extract android to any directory of your choosing, then cd to tools in the android directory then double click on emulator!