The biggest improvement will be in the overall speed and performance of the app. Nokia says it is using progressive rendering and other optimizations to be able to get city pages to load four times faster, and offline maps will load as fast as your hardware can handle. Nokia has also added mouse and keyboard support for those of you on laptops, but obviously the touchscreen controls are still intact. The update will have support for high-resolution satellite imagery, so you will be able to see far more detail when zoomed in. Lastly, the app will now store your search history and routes that you've calculated, and place results lists will be able to be sorted by distance or rating.
Nokia says that the update will be rolling out over the next few days starting with North America and Europe. It looks like a pretty solid update, and will definitely be nice for users who may not be all that impressed with Bing Maps, and who can't get an official Google Maps app for their system.