Recently the update leak for the AT&T Samsung Galaxy Smartphones, recently an Android 4.3 firmware was leaked for International variant of Samsung Galaxy Note 2. Samsung is expected to be rolling out the updates for the users in about November.
The new version update for Android 4.3, brings in a lot of changes. The User Interface is changed alot, and like the updates for Samsung Galaxy S4, Samsung Galaxy S3 many features are similar, like KNOX, and also Samsung Wallet has been included in the pre loaded apps in the new firmware.
Also the new firmware is available for download for Note 2 N7100. You could download it, and try it now. But do keep in mind the it might not be as smooth because it is still in the testing phase.