Update: The Gmail app has been pulled from the App Store.
It's official, and it has iPad support.
As is widely reported, the app is, however, largely underwhelming. Offering what is essentially a front-end for the web interface, Google's Gmail iOS offering does little to argue its case in favor of Mail.app. With no support for multiple accounts, and an immediate notifications error, it appears this is a case of "wait and see" before deleting your Gmail accounts from your Settings pane.