It seems as if the Gmail app on 2.2 differs from my experience with the one on 2.1, in that, when I receive a new email on 2.2, I either open the app via notification or icon on the home screen and am presented with the open new message. I don’t like it and want gmail to open to it’s inbox – nothing more.

What works for me is to always exit the gmail app by using the back key. No matter which screen you’re in, using the back key to get out will let you open gmail to the inbox, not the most recent message.