Found this in the iPhone App Store:
GPS by TeleNav for iPhone 3GS, iPhone 4, iPhone 4S, iPad Wi-Fi + 3G, and iPad 2 Wi-Fi + 3G on the iTunes App Store
So there IS TELENAV for the iPhone 4S. It doesn't come pre-installed but can be downloaded from the App store.
GPS by TeleNav for iPhone 3GS, iPhone 4, iPhone 4S, iPad Wi-Fi + 3G, and iPad 2 Wi-Fi + 3G on the iTunes App Store
So there IS TELENAV for the iPhone 4S. It doesn't come pre-installed but can be downloaded from the App store.