How To Use Vanilla Android Launcher Instead of Touchwiz
So playing around I gigured out how to switch it:
Press Menu > Settings > Applications > Manage Application
Press Menu > Filter > All
Scroll down to TwLauncher and tap that, then tap Clear Defaults
Press Home and you will be prompted to select Home (Vanilla Android) or or TwLauncher (Samsung TouchWiz). Check "Use by default for this action" to set Home as the default Launcher if you like.
If you ever want to undo the process, simply repeat the process but go to Home instead os TwLauncher.