The full change log include:
Power Saving Mode: turn off GPS when the app runs in the background (except
when used in guide mode.
Back to my position and distance measurement: one-touch access to your
current position as you explore or zooming of the map also shows the
distance from the current position
User Interface Enhancements
Bug fixes http://wmpoweruser.com/nokia-drive-beta-for-wp8-updatednow-easi