It's been a long time coming, hasn't it owners of AT&T Galaxy Tab 8.9's (SGH-i957)? All other variants of Samsung's Galaxy Tab 8.9 have been sporting Ice Cream Sandwich for weeks - even months in some situations. And it's finally your turn. I'm genuinely happy for you. Seriously. I am. You waited it out, and you deserve this.
But here's the thing: the update isn't coming OTA. Instead, you'll have to pull this one through Samsung's proprietary Kies application. Don't worry - it's not as bad as it sounds. Just plug your 8.9 into the computer, fire up Kies, and let it work its magic.