TouchWiz UI, and of course a batch of security patches. Many of the widgets have been updated too, so your Galaxy Tab 10.1 will certainly look fresh after the update. For those of you that currently use a home replacement launcher - you may not notice any change at all.
Tagged: coming soon
spotted here. Last we heard it was coming sometime in late August possibly on the 25th but surprisingly no one noticed it missing. With the Bionic and HTC Vigor on the horizon we must have forgot about it.