Well, you already know it's not Jelly Bean, but T-Mo is sending an OTA update to the Galaxy S III right now. It's a minor one, mostly dealing with some Touchwiz stuff you likely don't use, as well as a behind-the-scenes tweak to pinch and zoom. Woo.

Current Version - Android version 4.0.4/Software version T999UVLJ4

The 12MB update is available via OTA right now, but if you'd rather use Kies for some weird reason, you'll have to wait until tomorrow.

[T-Mobile]