I only noticed this yesterday as I had a reason to turn on 'USB Debugging'. Since allowing 4.2 to download, the 'Developer Options' item has disappeared from the Settings menu. However, it's only hidden, not gone. The secret is to go to the Settings>About Tablet option, and at the bottom of the page you'll find Build Number. Tap on this item 7 times and you'll see a countdown and the end of which you'll get your Developer Options back!