Google in a tweet announced the release of a HTML 5 optimized Music Beta player for iOS 4.
"When you first launch the webpage, Google asks you to allow for 25mb to be stored on your device. After, your acknowledgement, you are presented with a full run down of all of the artists you uploaded to the service. Once you have selected a preferred song, you are taken to a "Now Playing" page."
Here are some screenshots:
[Photo credit: iPad Matt]