AU: Google Voice isn't available in Australia. Yet.-EH
It has what you think an official Google Voice app has: push notifications for new texts and voicemails, something prior GV apps couldn't quite handle without a third-party workaround. Get it now! Will update the post in a second with impressions.
Update: The video is above. What you can see is that Google, although making the app barebones, made it pretty slick and fast. Texting and calling work exactly the way you want it to, but you can't really change a lot of settings from the app. There's no way to add new phones or change calling groups or schedules or anything. But for the very basic functions, this is a winner. And it has push notifications as well as dialing from Google's direct access numbers for decreased connection times. [iTunes]