The data is updated. That is probably the most important difference.
Here's a summary of new features
New Features in MapPoint 2006
• Completely Refreshed Data
Use updated geographic and demographic data sets in MapPoint to display trends and illustrate key points on maps.
• New Advanced GPS Features
The new GPS task pane uses information from your connected, compatible GPS device to display your current location, speed and traveling direction.
• Voice and Text Directions for Windows XP Users
New Driving Guidance finds your location from a connected GPS device and combines it with a route you have created to give you voice-prompted driving directions.
• Microsoft Location Finder
New Location Finder uses your computer’s wireless network capability and a database of known Wi-Fi access points to display your location on maps, even if you do not have a GPS device.
• New Map Style for Low-light Conditions
New Map style for low-light conditions makes it easier to view maps on your laptop computer.
• Pocket Streets
Microsoft Pocket Streets makes it easy for you to create custom maps in MapPoint and then export themfor use on your Microsoft Windows Mobile®–based Smartphone or Pocket PC.
Also take a look here, there are links to a lot of external articles and discussion --
http://www.mp2kmag.com/update/mappoi...17/#mpnews_sec
Eric