It looks like it is a WPF application with an updated look overall and a few menus are moved around.
From the help file, this is what is new, besides updated geography information, which looks like can still be 'backported' to earlier versions:
Send to Mobile
Now you can send information—such as the address of a business—from Streets & Trips directly to a handheld device, such as your phone. Then, you can access this information from your phone at any time during your trip.
Display Entertainment Online coupons
To save you money, Streets & Trips has partnered with Entertainment Online to present valuable special offers in many towns across the United States and Canada. Now you can see which Entertainment Online coupons are available for places on the map.
Online content
When your computer is connected to the Internet, Streets & Trips provides seamless links to the latest online content available for the places and businesses that interest you. This content includes restaurant reviews and ratings, addresses, articles, and more. Even when your computer is not connected to the Internet, you can still access information about places within the Streets & Trips program, which contains information on more than 1.5 million businesses and points of interest.
