Nokia has released an update for Maps for Lumia Windows Phone devices. Windows Phone 8 brought in the ability to update the downloaded offline maps whenever available. You can go to Settings->Applications->Maps->Updates to install them. Installing latest Maps will bring you the latest local map tiles, POI data, etc, to your device so that you can be always up to date even when internet is not available.
Thanks to everyone who sent this info.
Â Update: Â The maps update appears to be hitting all WP8 handsets, with users with the HTC 8X also reporting receiving the new data.
Thanks Sean for the tip.